Multiple holes in joists for pex?

In re-plumbing with pex, keeping the manifolds in the warmer part of the basement will require drilling multiple small holes through the rim joist for the branch lines that will run through the unheated crawl on their way to the fixtures. I understand the rules about where and how big to drill -- but is it ok to drill many 3/4" holes in line 1.5" apart through a joist? I haven't run across this issue in my Google and YouTube searches.