I begin to understand why most dance balls are still entirely filled with classic non-mesh avatars. And that isn't because nobody wants to donate their own avatars as NPCs nor make new ones.

It's because an NPC would have to work under any given condition with no clipping. But no matter how you approach alpha-ing, it's potentially unreliable.

Alpha cuts have the disadvantage of requiring scripts to work. I mean, they don't even always come with you when you Hypergrid or when you simply teleport to a place on a different region server. And what do you know, your whole body is visible again, and you can't even change that without detaching and re-attaching it which makes certain imported SL bodies blow up. And I'm not even talking about sims that don't allow avatar scripts yet.

Alpha masks are more reliable because they don't require scripts. However, they only work until some region server decides it's a good idea to change the alpha mode of your body from alpha masking to none. This is nasty on avatars already. Ruth2 v4 and Roth2 v2 let you restore the alpha mode with the HUD, but only if avatar scripts work. The same will go for the Max bodies in development. As for everything else, you'd better have backups with an intact alpha mode. But if this happens to NPCs, no chance to fix them.

If you want NPCs to be reliably devoid of clipping under any given circumstances, you have to build them from components that won't cause clipping. If you want such NPCs for a dance machine, there's the extra challenge to make them believable dancers. Easy for beach parties. Even easier for nudist places. Very tricky for ballrooms. Unless, of course, you reject a decade of avatar advancements and go for classic content on the system body.

Juno is occasionally working on NPC versions of herself that are made of content which suits today's general tastes more than what she uses herself, like a Simona body (sorry, no Legacy, you can't really dress a Legacy avatar like Juno), an EvoX head and an EvoX skin (sorry, no Doux hair because Doux themselves have never released a short bob, so the unrigged Paige hairstyle is the closest to Juno's hairdo in SL mesh). She's doing that to have something to donate to reduce the lack of newer NPCs. But her NPCs will have to rely heavily on auto-alpha. Testing them could be interesting, much less actually deploying them.

Good news: Invisiprims are coming back to at least Firestorm!

Better news: They don't need a script anymore. They're activated with a checkbox in the viewer.

They're already available in the current public beta. Here's proof:

Sexiness does not equal as much bare skin as possible, classiness even less so.

Likewise, going bare-legged in winter is quite a bad idea.

Dare to wear BoM nylon, ladies!