Depends on tires. If you run street/hybrid tires of closer to stock size and not of very low threadwear (thinking of PSS grip level), it's not as if stock suspension is unusable and not as if changing out springs or coilovers will improve one's laptimes lot. Very same money spent to improve driver himself will net more return
And you mentioned 10 trackdays/season .. that sounds to me more then sufficient amount to switch to track oriented/dedicated alignment, as that's were most of wear will happen. -1.2 front camber seems insufficient for that, and while intended -2.2 a bit better, but i'd aim for at least -3 (and rear -2.5). Thus suggesting to buy in addition to those powerflex bushings also Pedders eccentric topmounts (if you want less NVH issues vs camberplates), or if budget tight, another camberbolt set for other strut hole (but would prefer pedders topmount + powerflex bushing + single set of camberbolts. I had sheared once camberbolt head, for piece of mind would like one of bolts stock full strength).