If OP cant use more than one disk at once, how can they benefit from mergerfs?

Mate I dont own any of them, but open source is easy life. Prusa uses marlin afaik which is awesome and you can always change to klipper which is even better imo. Im in this hoby for 10+ years and prusa was always recommended by users. Bamboo looks amazing, but I wouldnt go for baby company with properary crap over big and famous prusa, the inventor of this kind of printers.

Also dont wait, just buy one. They didnt change that much hardware wise after adding heated bed. In my opinnion 3D printers are much better now compared to 10y ago, but 90% because of the community. Hardware is better, software is much much better, but community is what makes it rly good for new people. It means you can buy any popular device and you will get better support than any company can even imagine. Even better if you go open source route.

Whatever you chosey there are plenty of resources online including Lemmy, arm yourself with patience and enjoy the ride