I dunno if this has been raised before, but i was just mucking about and i wanted to share.
Ive created a file using google slides using one of my maps. I've dropped a link into a online match thread. my thinking is that the dice roll would remain in the thread but the map could be open in another tab using the 'sharing link' and either player could then edit as they go along. its not a pretty as some of the maps the regular players use but its easy done and avoids the 3rd party issues in some what. Give it a try
Ive just copy/pasted slides and moved the appropriate text fields to update. Can simply be done through chrome or off android. I did the whole thing off my phone.