In my experience, every neg requires its own filter pack. Sometimes you get lucky and the color balance of one frame will be the same for all other frames on a roll, but for me that is the exception. The filter pack for one frame at a given enlargement will change when the enlargement changes and when you switch papers or paper batches. Some will say they always use x-filter pack for x film, but I have never seen this to happen in my experience.
My workflow was to do a contact sheet with the enlarger set for about a 12x12 print using my paper of choice. On the back of the contact I would record the time and filter pack. This was generally a good starting point for future prints.
one last bit of information. I have never used unexposed, but developed c41 film base as an aid to enlarging. It may work wonders, but i've always thought if a layer hasn't received enough exposure relative to other layers than you haven't solved your problem. I used drilled out neg holders that allowed for a verification border and or glass holders with a mask created with tape.
on one neg holder I drilled it out and filled it back in w/ clear epoxy. Being relatively neutral you can see the color of the filter pack bleeding through on the edges:
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