What are/were the names of the local water, electricity, gas companies?

Either that or a prototype slime monster trap...

That would depend upon your application, your long term support needs, whether you need a widely available database which is hosted by multiple providers, whether you need a feature that isn't available elsewhere etc.

Otherwise it's a bit like asking "what type of rope should I use for my application?" Are you mountaineering or tying your boat to a dock?

I've never seen this enforced so I doubt changing the number will make any difference other than reminding people not to idle their pollutes...

Is this "support" in the sense of "can this sequence of code points be rendered correctly to the screen"?

OS and font dependent.

Also turn off Hyper-V if using Virtual box. If you check out the documentation there's some warnings about possible poor performance when Hyper-V is enabled.

Not sure if it's helpful, but bigclivedotcom recently reverse engineered a toy with vias between layers for thermal transfer:

https://www.youtube.com/watch?v=qTeZVqoVe7U&t=257 at 4:00+

Hadn't seen this technique in use before - but I know just enough to begin to know what I don't know...