Relationships are about give'n'take; about accomodation, compromise.

So re cross-dressing.  This may be something that Subby has to "give".  But could there be a slight middle ground?  Would you be OK with him wearing knickers instead of underpants?  For me, part of the thrill of cross-dressing is "what if someone who knows me sees me; I'd be humiliated". So wearing knickers can get part of the way there.  This may be a way of scratching that itch without it being in your face.  Push it a little further; stockings instead of socks?  At least while he's out of the house (work, errands, whatever...).

You may even be able to frame it, mentally, as an extra way of giving you more control; if you throw away all his underpants (or lock them up in a box) then you're controlling his clothing.

Re ED.  I don't have a lot of experience here 'cos I've never found penis-in-vagina (PIV) sex that interesting so the lack of penetrative sex hasn't bothered me too much and my Mistress has had plenty of fun having me tied up next to her, pulling on my nipple clamps while playing with her Hitachi Magic Wand.  But I've heard of other couples using a strap-on as a substitute.  You can even get kits where a mold can be taken of his penis and that used to create the dildo.  He can then wear that (over his cage, if necessary!).  It's not the same, and requires a bit of fantasy in both your heads, but some people have reported success.  You can then joke that you own both his dicks :-)

Just some thoughts!

Yes.  The lockee sees actions performed by the keyholder; eg add 2 resets, add 5 freezes, add 20 reds. 

However if the lock has been marked as hidden then the lockee just gets told that a change has happened... but doesn't know what the change is.

Overnight erections are natural.  3 or 4 per night is not un-normal.  So overnight cage erections are a consequence.  Some people claim it goes away... it doesn't for me.  My longest lock is over 170 days and I was still having overnight erections.

What helps, for me, is ensuring I pee a lot before bedtime.  Also shaving pubes (not totally smooth, but very short) helps because what wakes me up is the pubic hair getting caught between the penis shaft and the ring and then on an erection the cage pulling forwards and so effectively pulling the pubic hairs.  Ouch!

Without the pain I can sleep through most overnight erections.

Some people have required "something else" when not caged.  e.g. make him go hiking while wearing a pair of panties and when you get home you can lock him up again.

In that way he's reminded of his position, and you're still controlling him.

I'm gonna come at this from another perspective.

Why do some people like to go running?  play tennis? Or soccer?  Chess?  Read books?  Listen to music?  Go to the theater?  Some of these I understand (books! Chess!), others I just don't get (running? Isn't that torture?).

Different people like different things; there's a saying "Every Person Is Different" (EPID).

So why is BDSM any different?  Just because it involves the "wibbly bits" and so is taboo to talk about ("shush; it's about sex! Can't talk about that!"... even if there's no "penis in vagina" sex involved, it's still considered sexual and thus taboo) doesn't mean it's inherently different.  Some people like it, others don't.

Almost 2% of people indulge in some form of BDSM ( https://pubmed.ncbi.nlm.nih.gov/18331257/ ) in a year.  So while this is a minority, it's not _abnormal_.

Why do people get into it?  Many many reasons.  "Dominant at work, submissive outside" is a very common one.  As is anxiety ("am I pleasing my loved one?"); having structure and well defined goals can make it easier and less mentally stressful.

For me, it's both mental and sexual.  I'm relatively senior at my company and have a lot of responsibility.  Instead of being the one who decides what is to be done, being tied down and flogged means I have just one responsibility (safeword if it's too much).  It's also sexual; just the act of my Mistress tying me down causes an erection.  She's joked before, as she's put me in a corset, then my penis is a sign that I enjoy this.

Similarly, chastity.  Paradoxically, the thought of being in chastity makes me hard... which also then makes it hard to put a cage on! 

Some men want to have sex with everything that moves.  Not me.  I get turned on by being controlled.  Being controlled, surrendering myself to someone I trust (literally when I'm tied down and can't escape she has the power of life or death, and I trust her absolutely) is an amazing turn on.

So.. EPID.

Now I do have one caution.  Some people get into this lifestyle because they feel they're unworthy and demand punishment and being demeaned as a way of reinforcing that status.  This isn't healthy, obviously.  But it doesn't sound like your husband is going down that path because "more attentive and interesting".  The positive sides of this relationship can be enforced; if you demand something from him and he does it well then praise him.  The sheer joy of knowing I've pleased my Mistress is good positive reinforcement.  "Carrot and stick"; you can't just be strict, you also have to reward.

From what you've written, it sounds like this is being good for your relationship.  You're communicating more, he's more relaxed, you're enjoying yourself....

This is sounding healthy.

I've come up with a newer version of my electronic safe, that can be used with chastity apps like this one (or Emlalock).  It takes a cheap ($30) electronic safe and replaces the smarts with an ESP8266 and a few components.  You might be able to build it for $40 or so.  It creates a webserver so you can set the combination (max 100 characters!).

https://bdsm.spuddy.org/writings/Safe_v2/

For people who like "dual locks" then this safe can take both 8 digit codes to create a 16 digit combination.  You'll never guess that!

(Note: "my Lady" is not the person on these forums known as "Lady"; it's what I've called my Mistress for the past 18 years)

She set up a daily non-commulative 1Day with 3G 3R 2Y lock.  That's relatively simple.  Frequently the lock would open and I chose "holder decides".  I've added reds, previously to keep the lock running longer, but they never last 2 weeks.

This past week, I've asked her to be nasty.

Today, 12 days into a session, she was.  +4R, +3Y, +3 Double, +2 Resets, +2 Freeze.

It's her birthday this week... I wonder if she's trying to fake me out, or if she's really gonna go through with this!  The longest I've worn this cage is 30 days...

Today I drew a red, which I consider a win... every red picked today is 8 reds not picked tomorrow :-)

I've fixed the documentation so that combination shows as strings. Thanks.

Almost :-)  The JSON now looks right, but the description still has "Will return 0 if not yet unlocked" in both places.