Almost all add-ons will not work in Kodi 19 Matrix/LE10.
Its down to the add-on dev to migrate from python 2 to python 3.
If your add-on fails in LE 10 beta, then email/github the add-on dev for a python 3 upgrade.
Sorry for stating the obvious, or repeating content in this " The most noticeable change for anyone using Kodi might be the new Python 3 requirement for add-ons. Kodi add-ons used to be programmed in Python 2, but that version reached End-of-Life on January 1st, 2020 and is no longer being maintained, so Kodi now requires all add-ons to run in the Python 3 environment." From here Sunsetting Python 2 | Python.org