@MCDuncanLab @futurebird Thanks a lot for help everyone! I took the #foldscope specs, eliminated a few options ("we got a USB microscope for kids ... but it's not very good", "how about this 200x clip you put on your phone? ... someone had tested it and concluded the magnification is closer to 2x in practice") and then I managed to somehow "search differently" than months ago because I found a new local #microscope shop, and they had a "do contact us if you need any help e.g. to select the first microscope for your child" ("I am a little bit past that age BUT can you still help? I mean of course it is for my ...inner child?").

They recommended this version as probably sufficient, it has 2x, 4x 'objective pair' and 'switch magification 20- and 40-times' changeable "with the oculars", I have no way to translate it to Foldscope's "3 Lenses (50x, 140x, 340x)" though. Is it 40x by comparison, or 4x40x = 160x?
https://prodi.fi/tuotteet/mikroskoopit/stereomikroskooppi-st-30-led-sis-akun/

This model also has a battery so I could 'scope away in disconnected areas too (in response to me spelling out my crazy field plans), but can be used on the wire as well. I may give it a shot! Whee! Exact species identification field dopamine awaits!