reciprocal links (does nofollow kill it?)

I know reciprocal links are not that powerful anymore or can even harm. I still use them as part of my backlink mixture and have never had any problems.

I am wondering now about that situation: I am receiving a doofollow link and link back to that site with nofollow attribute. Will the inbound link be more powerful then?

to build some authority, I do link manual link exchange (waste a lot of time, but I get a few high DR/RD links).
however, I put their links on nofollow, no index and not linked /links/ page

it is very slow. but it works - for me .