I've been a reluctant passenger on this route a number of times, but all of them pre-Covid.. After the first trip I swore I'd never do it again, but I climbed off that high-horse - it's the simplest way of getting to Sao Tome from Europe, and travelling in business-class takes the edge off the awfulness.
Touch wood , there.have been no problems going out, apart from those associated with bussing to a remote stand at Lisbon. Coming back though is as ghastly as a night flight with an intermediate stop sounds. Twice the ACC transit has been chaos, with excess Y passengers taking up the free seats in J.
Sao Tome's airport is tiny. There's no lounge.
Non-stop, even on a regular narrow-body, would be wonderful: on a lie-flat bed it would be a dream. And I rather think a dream is what the new schedule will turn out to be - though a lot might depend on how the route development is funded.