Each character is represented by a number of datapoints stored in the firebase db on the backend of Roll20. Any datapoint associated with the character will be written there. So you have a "sheet" regardless of if you have a "sheet"... if that makes sense. The HTML is the presentation of the data, and is a part of the code that drives how that sheet works in order to do things like autocalculate, etc. But even if you don't "create" a presentation/look for the sheet, the ability to store data will be there. Specifically to CSA and buffs... those are probably (I haven't looked) checkboxes that are getting enabled/disabled. Checkboxes are, again, just a presentation of the data behind them, and one you're only going to get by having it built into the sheet. Ultimately, I think the data behind a checkbox is just a -1 for true and a 0 for false, so you can, I think, throw an attribute at a generic sheet and tell CSA to "toggle" it. The presentation won't be pretty... and you won't have sheetworkers there to take action based on the value of the field changing... but you should be able to toggle the value. I think.
