New Unusual/off-beat Gear

Don't think that's true.  CAPI was taken to court over a patent on a knob, they changed the knob.  They could've won the knob suit given enough $$$$$$$$$$$$$ thrown at it, but what's the point?  Design patents have a shorter 15 year term than utility patents which are 20 years. After that, it's open season.  

If there was money in lic IP to clone builders Neumann, AKG, API and Neve would probably not exist today as manufacturers, there would be more $$$ collecting lic fees and protecting IP.
What IP is secured is pretty expensive because it has to be agreed upon by both parties and the IP holder usually looks at it as a lost sale. It usually only happens among friends ( our sister company was the first to license the Aural Exciter from Aphex).

In the states the UL approved PSU is really only a big deal in California where earthquake code requires anything permanently installed in a public building must be UL approved. However I have never heard of an inspector digging in the back of a rack for UL approved stickers.
Most manufacturers view the UL approval as a secondary benefit, the primary being cost and the advantages of easily replaced in field PSU and low EMI in test bed situations.

HA, that is total BS, having been part of the leadership team of one of the US largest dealers, knowing the leadership of most of the largest dealers, nobody has ever refused to carry a piece because of UL listing. If this were the case non of the small boutique tube gear would be sold through dealers. Most small scale manufacturers can’t afford the cost or the time it takes to receive approval. So unless you are using an approved OEM PSU you are probably not approved ( internal PSU’s that have been approved also count). So pretty much anything that requires a custom PSU is not going to be UL approved. The exception to this will be contracting install aimed products, but I know of a fair amount that are not.
For many the 500 format has been a workaround, but only a handful of 500 racks use approved PSU’s so for many it has been a pain in the ass. A common workaround/ loophole in the CA earthquake code, is to mount all the unapproved pieces in “ portable “ racks and state they are not installed permanently, “ see that rack isn’t plugged in or hooked up” well today it isn’t so it’s not permanently installed. Legal? Well probably not but most inspectors will let it by but again I haven’t heard of a single inspector who looked.
I will admit that on bid proposals and for substitutions I know dealers and consultants who will only use UL approved equipment and will state so, I also know that this has influenced decisions inside and outside of California. For bids in CA I know proposals that have included a copy of the statute.
Only in the case of large scale installs is it worth the dealers time to explain that not meeting this code could effect insurance claims or liability, if I’m just replacing a piece of gear it’s probably never going to be addressed. Frankly I worry more about the guy who is going to hang a speaker either by its handles or drilling a hole and screwing in a standard open eyebolt with wood screw threads into a fiberboard cabinet and use generic non millspec hardware than if the amp is UL listed.

It’s not total BS, because it is the law in CA, but most don’t know or care, but just a quick search of Back panels will show how little attention is paid to it. I also seam to remember like ROHOs there was a computer peripheral dodge as well, ironically in this case in our arena most of what plugs into a computer meets both.

I think if you manufacture/mass-produce an item that imposes a safety risk (i.e. plugging into 100/120/240v power qualifies...), and you choose to skip the UL certification (or CE compliance in non-US countries) then you probably better have a very good lawyer (as I'm pretty sure that opens you up to get sued pretty easily).   At the very least you should print a bogus "UL" stamp on it like many of the shady Amazon items.