Honestly I would not recommend a Jolla/Youyota tablet in this case, at all. The only requirements it fits is that it has a screen size of 8 inches and a GPS. Its performance is not good at all, in fact quite the opposite: graphics-wise the lag is unbelievable (instead of smooth movements as in other Sailfish devices it's all jumpy, and the screen has to be thoroughly wiped every couple of days if you don't want to get randomly registered taps and swipes), and the battery life is very, very, very poor (it lasts precisely 2-3 days just laying there, completely unused). It also doesn't have a SIM card slot, so would need tethering, and considering the mentioned Nokia Asha, this is not an option.

Maybe, and hopefully, these are software bugs that can be solved (although the screen having to be cleaned certainly isn't), but for now it's unusable for lay(wo)men.

Regarding the scripts on Indiegogo, I've found it 'only' needs indiegogo, iggcdn and stripe for the site to function.

Regarding the apkmirror thing you mentioned, you can use Aptoide instead, it's free software and works quite well.