If I'm over 30 feet back, I have no business recording ;-)
It's quite easy to be further than 30 feet back when you also have a soundboard patch and are also recoding an audience with the same deck (unless you get a patch from onstage and the microphones are on stage too). I often find myself trapped in a less than desirable location audience taping wise in order to get a soundboard also...
Most of the time, the board is at stage lip, and my mics are also at stage lip, or on the stage micing a particular amp or overhead drums. This question is geared for the times I am in a small venue that the SBD is on the floor, but it's a small enough venue that the SBD is 20-25 feet in front of the stage. There are very few times that I would be further back than that, but it certainly happens 1-2 times a year.
I have never lined up the channels in post, because I never felt I needed to. Now, I'm thinking that I may need to from time to time when recording in these small venues that I'm 20-25 back at the board. How would I correct the timing in post?