Itch provides up to 2 GB which can at their discretion be increased. All they are asking for is 10% of your gross revenue. This is extremely generous and 2 GB goes a long way in the hands of competent people.
We do not know what their guidelines are for increasing upload limits, or even if there are any. My belief is that it is up to each agent to decide based on such factors as:
- How you word your request
- How much effort you put into your game page
- How reasonable the game size is
- How generous they are feeling today
- Your posting history
- How stressed they are
Reasonable request + Politely worded e-mail + Long Queue => Upload limit increased no questions asked