Exposure counts as a source of Advancement, which can be replaced by any other source of advancement.
Only one Source of Advancement per Season.
Lab Work does not disrupt advancement, only Time. Visa Versa.
An Adventure/Exposure that takes less than 10 days does not disrupt Lab work, one of up to 30 days has the penalties as described in RAW.
Same goes for forms of Advancement (other than Exposure/Adventure). Studying for part of the season reduces the XP gain by fractions of one-third (two month study) or two-thirds (one month study).
It is theoretically possible to abuse the system, study for one month, work in the lab for two, and smile sweetly and claim you are not a munchkin. I actually don't mind if you do, because the maths are difficult and results less than spectacular. But you may be in a crunch for time in a situation some day.
Concerning Potential Multiple Sources of Advancement
(such as if you had a grand adventure lasting a week and studied the rest of the season, or had three adventures and practiced spell mastery).
The XP gain equals the total of the Highest potential source, xp may be distributed amongst all the activities (to a limit of that activity's source quality).
So, for example, you study a Quality 10 Magic Theory Summa, but in the middle of the season you have a two week adventure involving politics in Byzantium, which is worth 15xp for things like Intrigue etcetera. You gain 15xp for the season, only up to 10 can be spent on Magic Theory and any number on Intrigue etc.
If the character has a virtue that boosts XP, it only raises that source.
In the above exemple, a character with Book Learner would have 2 xp sources: 13 (10+3) xp from the MT summa, and 15 from the adventure.
He would thus gain 15xp, and would be able to spend up to 13 on Magic Theory instead of only 10.