From what I assumed, the subliminal is full of modules following each other. So, in listening the whole subliminal, you get the exposure of all the modules. If you get interupted, you miss certain parts of it. Not a big deal, if you listen to it multiple times in your stack, because sooner or later you will get an exposure to the module you missed the first time at least once.
It’s easier if you listen to it in night, of course. The more condensed is your stack, the better. For example, I only listen to Emperor v2 and might get a stack module or two if I believe I need the extra coverage for certain stack module targets. When you start adding more subliminals, only then it starts getting more important to get more uninterupted exposure, because if you start getting only 15 minutes of the 40 minute subliminal and the rest are completely different subliminals, that makes you miss out important parts for the one you missed, therefore might start to get less effective.
TL;DR: If you have 1-2 subliminals and you miss like a minute or 10 here and there, no worries. You will get exposure to the ‘‘missed’’ modules sooner or later at least once.