Too true, too true. Ball pythons are rather secretive and touchy little snakes.
I agree with all that... but I will add, just in case you are one of those (like me) who can't just go get a new enclosure and such, that you can keep your little one in that 20L tank as long as the tank is secure and "busy" with two identical tight hides and not much open space. Good hides can be as simple, and cheap, as plastic flower pots cut down with an opening, or even flower pot saucers for the really little ones.
But, yes. Make sure you have a nice secure enclosure, don't handle until they've eaten for you at least once, and up that prey size to something a bit smaller than the snake is round in the middle.
Good luck!
Oh, and as for the feeding in another enclosure: I do it mostly because it helps the ball pythons know when it's dinner time. That, and the pre-scenting. My snake room is lit in some way all the time, and they like it nice and dark for feeding so I put them in nice dark tubs. The corns don't care, so they get fed in their homes. It really all comes down to individual snake preferences.![]()