The 0.2mm nozzle has less material flowing through it than the 0.4mm
You can only force so much material through it before your nozzle before the extruder starts skipping
Think of a garden hose, the 0.4 mm nozzle is the hose flow unobstructed. When you put the finer nozzle on the hotend it’s like putting your finger over the end, the pressure behind the nozzle goes up.
Try printing at the same speed as the 0.4mm nozzle (this is what I do) and make sure that your slicer is properly configured for your new nozzle and it should adjust the flow so that it doesn’t chew the filament to bits in the extruder.
Also 0.2mm nozzles will clog a lot easier than a 0.4mm nozzle due to the smaller opening so you need to be pickier about filament.
You say you think you’re having heatcreep issues, what exactly are the issues you’re having?
Literally I’ve only ever seen 1 as litter in my neck of the woods and it was totalled when I found it
It’s been years since those things were normalized how have I only seen 1‽
I mean good job folks but damn