Cool. I played around with a similar google spreadsheet a while back. Yours looks a whole lot more polished than mine

Mine started out as my own modification of the Sane and Simple Bitcoin Savings Plan. Conceptually, right now, my idea would be to create a bot that does the following: whenever X bitcoin is sold at price P for D dollars, create a list of buy orders spread out over a wide price range which, when totaled, would use the entirety of the D dollars to buy back X + a little extra bitcoin. Example: if the algorithm sells 1 btc at $1000, it automatically places buy orders for $200 worth of bitcoin at prices $900, $800, $700, $600, and $500. If the price falls all the way to $500, then you will have used up the entire $1000 to buy back bitcoin at a cheaper price. You can make it as granular as you think the bot and the system can handle. The interesting problem becomes: what is the ideal way to distribute the buybacks? The answer should be determined by what you expect the volatility to be, so that you can maximize how much you profit from volatility. If there is zero volatility (steady rise to the moon), you're basically just implementing the SSS.

One other thing: whenever you buy bitcoin, your bot should do the same thing in reverse, i.e. it should create a spectrum of price points where you sell it all back, but at higher prices. From an algorithmic standpoint, just flip the BTC/USD pair and treat buying btc as if you are selling USD.