The "cold and flat" thing used to be my whole take on stuff like this, not gonna lie. Then I tried it myself and realized I was just scared of how much the nouns had to carry on their own. It's a real exercise, it just shows you where you've been hiding behind fancy words.

1% magenta in reflex blue stops it looking dead.

Skip buying lists from random vendors. Run a test batch of 100 emails through a verifier before you pay for the full 5k, and ask them for a sample that hasn't been cleaned. Honestly most of these list sellers recycle the same dead data and just rebrand it. Get proof it works first or you are just burning cash and wrecking your sender score.