I forgot to wipe my farmhouse cheddar with vinegar before waxing. Fatal mistake?

No I never do, vinegar is used if u know the cheese surface is contaminated.

u could use vinegar or brine to remove any mold if any…

I’ve never used it either, nor have I used a salt water wash on a Farmhouse Cheddar.  Guess we’re all assuming that you had no mold on it before you waxed it - unlikely unless it had to dry for an excessive time.  I have had to wash my Manchegos due to mold buildup in the first week, but they are considerably more moist.

I don’t wipe them down before waxing either, unless there is something evident.

yes this is what i said… and after wiping, u should allow few hours to dry again before waxing