When I do drawings for mechanical projects I borrow a process DaveR talks about.
Use the Solids tools in Sketchup. A solid can be added or subtracted from another solid. DaveR calls it making a cutter. To cut a hex hole through a curved cylinder; draw the curved cylinder, then draw another solid the shape of the hole, push/pull to a length long enough to extend the ends beyond the cylinder diameter. place the hex “cutter part” to intersect the cylinder where the hole is to be. Then with solid tools subtract the hex from the cylinder.
Added benefit using solids is it forces one to keep you drawings free of bits and pieces of unneeded geometry. Solid tools has many different ways to work wit solids.
Search on “cutter” to find some of DaveR’s posts.
This process has worked well for me.