@dannytaurus
Multiple wavetable synths will use a lot of memory.
Christoph's WT engine creates mipmaps (multiple antialiased copies of the wavetable).
If you have multiple WTs loaded into separate WT engines simultaneously, each one will have multiple copies of the wavetable.
However, this memory is probably still small compared to say, a regular multisampler... However 100 wavetables is gonna get big I can imagine you could pass the GB mark of ram usage.
Can't speak for cpu, you can try it but I'd assume cpu is okay as long as you don't have the inactive synths do any processing when silent.
If you are trying to acheive clickless swapping or something (idk if the WT engine does this already? Or what your goal is with having multiple WT engines - fast loading maybe??? No silence dropout???)
You could just have two WT engines, keep one silent, and use the silent one to load the new wavetable, once ready, volume fade between them. Then you get a seamless handover to a new engine.