Congrats on the boiler system. I installed my own Froling this past spring. I only have about 125 operating hours on it and its connected to 800 gallons of unpressurized storage. My boiler is the FHG model and was one of the very last few sold by Tarm. The model tag on the boiler jacket even says S3 Turbo but it has the older generation FHG controls. I love mine and how simple it is to use. Mine has the ability to calculate how much wood to load for refueling like yours but my understanding is that the calculation is based on storage tanks configured like your pressurized tanks. Without those tanks the calculation is a gross estimate at best. Even in the short time I've operated mine, you learn to load based on what temps you see in your tanks just like you would learn how to load your woodstove. Please tell us a little more about your solar panels (brand?). My goal was to eventually have solar thermal to heat my solartechnics storage tank during the summer for DHW.