Yeah I picked up a Park set ages ago when rotor bolts went to T25, most are still very sharp and good, but like you I’m building up the nice ones as I go for the shed tool kit, still a big step on from 2mm allen key bolts, most of mine had a screwdriver slot in them.
I know it’s been done to death, but I wanted to bleed my lad’s Tech M4s, and one of the screws holding he reservoir cap was stuck. A cheap T10 was deployed and I promptly rounded the bloody thing. SO, knowing I was now having to revert to dark arts to remove it I contacted Hope Service who gave me a number to ring them on. A guy called Rob answered, and we discussed options for removing the stuck screw, and I said something along the lines of, I don’t want to tackle it until I have a new screw to replace it. Rob then asked for my address, and said he’d post me out a new reservoir cap, screws and diaphragm, as it was possible I could damage them (in fact would have to in order to hacksaw a slot in the screw head) Wouldn’t take any form of payment, and explained they were jealous of their Customer Service reputation, so didn’t charge for parts under these circumstances.