Tried printing something taller, a vase from here: https://www.thingiverse.com/thing:570288. Scaled 2x so 30cm total height. Print time ~24h. Filament ran out @24.7cm so I edited the file to continue from ~correct layer with blue PLA. Sadly the blue part came off, not sure why because the rest of the blue part holds together fine, even though the print quality is quite bad at the top.
Also seem to having some problems with the extruder, had to disable linear advance because the motor was skipping steps with low print speeds... again not sure what is going on, the motor is a quite beefy thing and driven by DRV8825 driver. Maybe try switching to A4988 as the other Dollo runs fine with one, with same motor and extruder design.

File is sliced with KISS, which leaves ugly gaps in the print. Probably didn't have proper settings for hollow print or something...

It's obvious that the frame wobbling around starts to cause visible problems when the parts get taller. So need to get the frame rigid.