is it safe to alternate between different brands of methylphenidate on random days, depending on need?

basically, im on 36mg XR at the moment. before that, i was prescribed 30mg of medikinet cr. it was too low for me so i was prescribed a different brand 2 weeks later (xiromed).

i still have half the pack of Medikinet at home. i am wondering if its safe to take that on days where i want a lower dose? since i have them anyway? or is it unsafe if i randomly switch between brand A and brand B (they also have different release mechanisms)?

like today i woke up late, now its 2pm. im just planning on going to a different city with my friend and practice driving. so i want to take my meds, but its 2pm already and idk if i want to take 36 whole mg with an effect that lasts 12h🥲

but im thinking that i could instead take the medikinet since its a lower dose + i swear after 4-5h they kinda stop working already. but i dont know if that is safe?