My experience with Marketforce is that they spell out very clearly what meal times are.
I can do a LTO at a particular MF ff shop from 11 AM to 2 PM. The park-in-a-stall shop has entirely different mealtimes, and I can do them from 11 AM to 8 PM. According to helpdesk, as long as I do the park-in-a-stall more than one hour after doing the LTO shop, AND it is in a different meal time, I'm good to go.
So I have LTO at 11 AM, and my cheeseburger at 2:30 and I'm golden.
So you could do the park-in-a-stall at 4:00 PM, and a sit-down restaurant dinner at 7:00 PM and be good.
Just carefully read the meal times; they are on the "see job details" page, you don't have to accept the job before you see the mealtimes.
Hope this helps.
And, of course, this doesn't apply to other MSC's meals -- you can do your MF shop, zip down the street and do the one for SeeLevel 15 minutes later, if you wish (and can bear it, LOL).