Parse Excel with UXP - are there best practices

I try to automate the creation of png’s for my colleagues. The source data I get from an Ecxel.
My idea was as a first step to convert the excel data in a json file.
It seems the the usage of the npm package “xlsx” won’t work inside UXP. I understand that since I learned that UXP doesn’t support Node.js.
So my question is:
Is there an idea of how to convert programmatically xlsx to json? Are there other packages to use? Or maybe am I able to call a node.js function to do that convertion job outside UXP?

My code so far (assuming in this case that the xlsx file is within my plugin folder:

async function readXLSX(){
    try {
      const XLSX = require('./node_modules/xlsx/xlsx.js');
      const fs = require("uxp").storage.localFileSystem;
      const pluginFolder = await fs.getPluginFolder()
      const theXLSXFile = await pluginFolder.getEntry("test.xlsx");
      const workbook =  XLSX.readFile(theXLSXFile);
      } catch (e){
      console.log("Error in function", e);

The result is “TypeError x.charCodeAt is not a function”.

How about resave xlsx into CSV instead?

I used that solution in the past when I wrote Extendscript’s. But there is a downside:
My colleagues are spreaded all over the world and are using Macs or PC’s. Based on that, the result of a .csv from same excel is not the same. German csv’s are saved with a “;” delimiter even if you force Excel to save “comma delimited”. Mac’s can’t read .csv’s created by PC’s and so on. It was a mess I hoped to get away and to deliver a “single button solution” for everyone inside UXP without preliminary steps.
In the end I want to deploy the plugin to all my colleagues to allow them to automate their work.