My gaming group are long time HeroLab Online users and have made significant investments in unlocking content there. Despite this, I am tempted by Demiplane because of it’s all-in-one interface and some of the other player-friendly choices Demiplane has made recently (the War of Immortals Playtest support, the Remaster upgrade program). I was actually ready to pull the trigger on buying the Rulebook and Lost Omens content until I realized that the AP and other adventure character options were locked in the character builder, requiring purchase of the full APs for access.
We are about to start Stolen Fate, and plan to use the unique backgrounds, as well as the Harrow sorcerer and Harrower archetype for this AP. We have already purchased the AP from Paizo and the modules on Foundry. The character options are such a minor part of the AP from a content perspective, that 1) purchasing the entire AP on Demiplane does not seem worth it to unlock these and 2) from a data entry perspective they should be relatively minor (a few backgrounds, magic items, spells, possibly an archetype or two).
I would suggest that allowing users to access these character options for free may actually help induce groups to buy the full AP on Demiplane if they haven’t bought it elsewhere. Use them as advertising rather than a deterrent to the platform.