There’s a small discussion about Freetrade happening on the Monevator site. (Monevator is a good UK-focused investing blog, ideologically leans toward passive/low cost tracking, probably skews older demographically than here.)
The discussion starts here Broker comparison: cheap investment platforms UK - Monevator - and immediately went in a “but is Freetrade’s model sustainable?” direction. Maybe @Freetrade_Team1 or someone would care to comment over there?