If you want a 150mm crank, would the easy way not just be to find a solid-armed crank and shorten it ?
it’s proving tricky to find any suitable cranks – all the nice ones are hollow, or scooped out (on the back – see deore)
my 165s felt a bit odd, not when pedalling but when flat pedalled- gives you a shorter stance. Whether better or worse I don’t know, but weird anyway.
conversely, my poor wife* has to put up with 165’s. if i wanted to experience just how weird/crap this must feel, i’d need to find 210mm cranks. No wonder her knees hurt.
(*she’s not even ‘that’ short, it’s just that for some reason the largest component manufacturers pretend that people under 5’8″ don’t exist)