what would happen if when servicing a set of rebas i put 15w fork oil in both the motion control unit(where it's supposed to be) and in foam wipers etc instead of 5w. I assume it'll still work but not as well? shouldn't really affect performance though?

They'll explode*

*Honestly? No idea!

thought as much. the only issue i can see is increased "stiction" although i still don't believe it has a significant effect anyway.

i think it will be better as it will stick to the foams better – no?

what would happen if when servicing a set of rebas i put 15w fork oil in both the motion control unit(where it's supposed to be) and in foam wipers etc instead of 5w. I assume it'll still work but not as well? shouldn't really affect performance though?

lowers/foams etc are meant to be 15w, damper meant to be 5wt. Assume your post was back to front?

just realised i got it wrong, i've got 5wt oil which i use to replace the stuff that leaks from the motion control knob. if i put that in the lowers i assume the issue is that it is more likely to come past the seals so will need replacing more often.