The Developer Hub does not describe how Datastore budgeting works in Studio when using it through the command bar or through plugins.
Budgeting in Studio increases per minute as it would in a live instance, but the maximum backlogged budgets are much higher than they are in-game (by a factor of >33x). This is useful for plugins because you can build up a lot more unused Datastore budget and do large batches of requests at once that way.
I have documented the behavior here which you can copy into a Developer Hub article: (linked at the correct section)