Why does nobody warn you about breaking in a new flat top before service

Bought a 48 inch flat top for the line back in March and ran it straight into Friday dinner, which was a mistake. The first two weeks it ran hot on the left third and I was burning onions while the right side barely seared, cost me maybe $200 in wasted product before I figured it out. Turns out the plate needs a slow seasoning over several days at low heat, like 250 degrees for an hour or so, not the max blast I gave it. Now it holds heat even corner to corner but it took a full three weeks of watching it. Any of you got a break in routine that actually works or is it just patience and burnt onions?