I made a Google Sheets spreadsheet where you can just plug in staked SPS, and see how it affects your RShares Modifier for all the SPL Ranked Leagues.
Please note: the formula is based off of what YabaPMatt posted in the Mavs discord earlier today. If you want to make any alterations, you can make your own copy of the spreadsheet to do so.
Below is a preview of the spreadsheet. Enjoy theory crafting!