For people looking for micro usb to usb-c adapters, I've just found these on Amazon (it's Amazon Spain, but maybe you can find them too on amazon.com or others):https://www.amazon.es/Unidades-ESR-Adap ... B01MRXPC2Q
On the comments, there's one user complaining about the tip being too long
Anyway, there appears to be some rubber around the tip. If that can be removed with a sharp knife, there we have the adapters we need.
I'm still looking for suitable jack adapters (at least some which can be modified with a knife, too). I'm waiting for some inexpensive ones I ordered on Aliexpress, but it's taking a bit long for them to arrive.