Hi evndenmvgcbk! 
This is an excellent first forum question!
I don’t know if any of this will exactly cover your situation, but it might help. All of this requires using Custom Goals, which is a Bee Plus or Beemium subscriber feature.
For a couple of goals (e.g. cardio exercise), I use Beeminder’s Meta Integration to have pairs of goals. In one goal, I enter normal datapoints (e.g. minutes) and let it build up buffer, without worrying about how much buffer. The other goal is the “meta” goal linked to the first one, and it encourages me to do work on the first one even when the first one has a large buffer. I wrote more about that a while back and I’m still using the first two goals listed there.
If you typically study in small blocks of time rather than all at once (so that each day you’re entering multiple datapoints, each for small-ish amounts of minutes), then this next idea might be useful:
I have a couple of goals where I use the “sqrt” (square root) aggregation method, which means that each day, later datapoints count for progressively less than my first datapoint.
For both of my sqrt goals, each datapoint is “1” if I did a thing; never any other value. I haven’t experimented with how it would work if the datapoints were minutes, but if I were in your situation, I’d try it, with my fingers crossed.
In case you’re interested, my “sqrt” goals are:
- randoms - I enter a datapoint of 1 if I use a random number generator to choose a task to do or a goal to work on. For me, this is usually a good way to overcome overwhelm and procrastination, so it benefits me to do it at least once a day, because after I’ve started on a task (ANY task, just get off the couch and do SOMETHING for hecks’ sake) then I can usually keep on with other tasks. Doing it more than once a day can be helpful, but not so much that I want full credit for every time I do it. The sqrt method lets me build up a little buffer if I really work at it, but the buffer never gets too big.
- ughs - Very similar to my randoms goal, but I enter a datapoint of 1 every time I think “UGH I don’t want to do that!!!” but then I go and do it anyway.
(Ignore the fact that recently most of my goals have had very few datapoints and lots of breaks. I’ve been in a significant slump and haven’t even had the spoons to use the tricks that I know work. Do what I say, not what I do. 
I think I’m slowly dragging myself out of the slump now.)