Which minimum tracking/spacing size is actually required for a 0.2mm gap between LQFP leads?
Any decent PCB manufacturer will be able to meet their published specifications. Will the yield rate be higher if you're not pushing the limits? Probably, but if you have the manufacturer test the boards, they're responsible for making sure all the connections are good, so they're not going to claim specs they can't meet.

Anecdotally, I've gone to 0.175 mm spacing on a 6mil/6mil spec without issue (for an accelerometer with 0.4 mm pin pitch), so 0.2 mm is nothing to worry about. If you want to be extra sure, the datasheet shows the maximum pin width as 0.27 mm, so you could take the pad width down to, say, 0.28 mm, which I've done when I needed to meet 8mil/8mil specs.