It sounds like these perceived limitations control your every move when it comes to music, and stress you out/bottleneck you. That is a bad way to go about things, being controlled by self-perceived ideas rather than spending that time making good music which is totally possible with what you have if you relax and open your mind.
Many famous and amazing artists use minimal gear without constant stress and desire. Imagine a homeless chap who laid eyes on his first sampler, they couldn’t dream of having more because they’d be living in a dream and probably make some emotional music.
Capitalism, the bittersweet union of “freedom”.
Here’s my recent motto: Make due with what you have, because if you’re meant to make it, well… then you can have whatever you want.
If you want limitless options, the Octatrack would indeed be my desert island music maker. Worry about an MK3 is silly. If you’re that worried try to get an MK2 on sale or second hand to cut your losses. Worrying about an MK3 takes you away from reality.
Better yet… if an MK3 came out tomorrow with actual improvements.
This horrendous “tomorrow” ideology is the thing that will keep you from making the music you want. The ONLY thing.