I spent maybe 7 hours, working with ChatGPT and a few SP users, making and figuring out the math and such required to conduct an accurate and successful MRSI (Multiple Round, Simultaneous Impact) fire mission with a modified version of my M301 Angurvadal. At a range of 62,134m, I was able to land two 155mm unguided shells within 100m of the intended target. This success led me to dig further down the rabbit hole of firing solution calculations and MRSI and whatnot, and I spent even more time with ChatGPT working in Microsoft Excel to make a functioning firing solution calculator. It was able to land shells within 100-175m of whatever target data input I typed into it. I took it a step further and made the calculator give outputs for two rounds, one at low arc and the second at high arc, to allow MRSI fire.
It integrates SimplePlanes' in-built coordinate system as well as altitudes and vehicle pitch/roll angle provided by the modified M301's gunsight to compute a baseline deflection and quadrant (traverse and elevation) as well as a modified deflection and quadrant accounting for inaccuracies caused by vehicle pitch and roll. It also provides the estimated time of flight for the low and high arc shells, as well as the amount of time to wait after firing the first shot before firing the second shot. It also includes a button (not shown in the image) to log the firing data in a separate D.O.P.E. (Data On Previous Engagements) spreadsheet.

Thank you for listening to my TED talk. As far as I am able to verify, this may very well be the first time any user in SimplePlanes history has succeeded in true MRSI artillery fire, and just the fact I was able to accomplish this kind of tactic in an aviation based game continually impresses me. I just wish there were more artillery nerds like myself lol