What would be the best approach to fetch calculated cells from a JS generated Excel file?

I am building a React web app that asks the user to fill out some inputs that are directly sent into an complex template excel file using ExcelJS. Everything’s working like a charm except that I must open the generated file so MS Excel or LibreOffice recalculates all the formulas, that means I can’t just call a cell getter from JS to fetch a calculated formula.

Unfortunately the file is far too complex to be re written in a simple formula directly in JS, it’s using matrices, graphs, references to other sheets, etc. It’s an old system that has not been reworked since back then and that I’m not permitted to change.

What would be the best approach to treat this case ? I would just like to fetch a single cell from that file, I know PHPSpreadsheet does that because I’ve already done it, would it be OK to create a PHP API that get the generated excel into parameters to fetch the desired cell and store it in a database so that I can get access to it via my react app ? It seems like an overcomplicated, or overcharged solution for what I want to do. I’m not against using something else that ExcelJS if you can provide me another library that can handle with complex excel formulas

Thanks in advance