I do it too, every 4-5 weeks
I don't think blood type makes any difference at all with platelets
Work are really good about it too, good cause and all (I do make my hours up though still) it does take about 2 hours ish each time including the paperwork
Everybody has a different program on the machines so time does vary they also vary it per person each time depending on current levels. I'm usually 'plugged in' for about 75 mins each time. You can get tingly and lips fingers from the anti-coagulant that ends up back in your system, which feels odd, but goes very quickly, I tend to get the odd sneezing fit from it tickling my nose too which is weird
The platelets regenerate very very quickly they could take them more often but you do loose some red blood cells etc in the process in the machine
iirc about 10% of what you'd donate if it were donating whole blood
4 weeks is about right for me though any more frequent could be a pain
You can do it less frequently too if you want, they’re very accommodating, appointments do get booked up though especially the one early and late in the day I usually take a long lunch as I work close to the hospital (10 min ride)
If you can do it and it fits in with your life get tested