Depends on what your goals are. If it’s muscle gain with minimal fat then aim for a constant mild to moderate energy surplus throughout the day. Of course when you exercise, energy output goes up and you have to eat more to maintain that surplus. Like you are saying, what and how much depends on how much work you do and over how long.
If your energy output is low (low reps, longer rests, short workout). Then your current meal plan may be adequate.
If your output is high but workout is short then a small to medium, hi-GI meal may be more beneficial.
IMO longer workouts can really benefit from sipping a Surge type drink throughout. This keeps your energy topped up and body out of the dreaded catabolic state that results during an energy defecit.
That’s the theory but you have to determine the what, when, and how much. Keep a food log and compare results otherwise you’re just guessing.