I currently build an Electron app that I ship as a universal binary for x64 and arm64 macOS builds. I see that Joplin uses Electron Builder which supports creating universal binaries if the Electron app is v11+.
Config for builder:
"mac": {
"target": {
"target": "'default",
"arch": "universal"
}
Electron:
"electron": "^12.0.1"
Builder version:
"electron-builder": "22.10.5"
This pulls both the x64 and arm64 binaries for Electron and bundles in a DMG