Pleased to report that the new version of the Firefox browser - Quantum - works well with Tablo’s web service, at least on Win10.
As promoted, FF Quantum is indeed (in my 24 hour experience) super fast loading most web sites, and it seems faster in loading Tablo screens, particularly displays of scheduled and recorded programs and the live program guide. It did this quickly with a large number of programs and without sync.
Two omissions, which I think may be because there was no sync: in my Recordings tab there is no “Most Recent” section and in Scheduled programs it isn’t listing episode titles (does have episode numbers, dates, channels etc.), which is inconvenient. (Titles are present in Recordings.) Otherwise all seems normal.