As a mech engineer doing mostly structural work these days, you are definitely solving an important problem, one which I both witness and experience first hand every single day. Excel is used a lot, but it's error prone and sucks for communicating your work (formulas and logic is hidden). Plus, trying to track down the latest version of some calculation someone did 10 years ago, digging down 29 subfolders on the common drive, ugh.

I do like projects like Jupyter (I used IPNB a lot during my masters), but it seems like 95% of my fellow engineers feel like python/julia/even matlab are "too complicated for something excel does". Which I disagree with (ever tried extracting eigenvalues in excel? or simply plotting a hisogram?), but eh. Programming is also less visual/graphic, which is one plus of excel (colors, fonts, layout of a spreadsheet do help with processing information)

I can't say if your solution is "the one". It's too complex a problem for that. But my personal feeling is you're tackling the right issues at the right angle. As good as your product is though, getting traction is going to be the hard part, by far. I wish you the best, and certainly hope I get to use your product some day.