I’m wondering: That topic you pointed out is from 2021 and Version 8.1.1 update from February 23, 2022 there is this:
IMPROVED: Compatibility of XStore Email Builder with WPML plugin
So, the answer is still valid? And what Version 8.1.1 update means?
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.