Reply by PurpLev

first and foremost – congrats on starting on this project :)

if your 1st edge was completely straight, than any treatment you’d give the opposite edge would follow the same irregularities. I would start by making sure 1 edge is perfectly straight. if not – joint it straight.

the opposite edge could also have been affected by misaligned TS, or a blade that deflected, or just cant produce a glue line edge. depending on the thickness of material – you could try to use the planer to clean it out and parallel. or a hand plane :)

-- ㊍ When in doubt - There is no doubt - Go the safer route.