Sorry I missed your question before.
Yes, I connected the case pin to the negative output pad on the driver on the opposite side that the negative diode pin is soldered to.
It effectively makes the build case negative.
Yes, I think it's much better this way. The thing I didn't mention is that because the tolerances of the module are less than perfect, there is some overhang of the copper part on one side or the other relative to the aluminum back which allows a pretty tight press-fit by hand. This makes it easy to remove if necessary but won't come out unless you want it to.
They are back in stock.
I emailed will when I returned from fieldwork this summer and he told me he got another batch in. I bought several just to make sure my pen needs were satisfied. I might pick up a few extras in case the supply runs dry again. It's not a bad idea considering how spotty supply for our things can be (drivers, hosts, other specialty items...).
Oh, yeah, I added some photos to the second post. Just a few - you've all seen the pen host before so it doesn't look any different.
I still need to send those plans to you, Rich... I'll get around to it.
My internet connection is a bit flaky right now so I can't check the ratings of similar switches.
They hold up just fine for high power builds. I've made pens like this with >1W 445s and a 600mW-ish 405.
If that's what you have in mind, be aware that it will run hot after a few seconds of sustained output.
DigiKey has a bunch of similar switches and they report the ratings as 0.05A 24VDC or somewhere around there.