> There is definitely a separate "Fast" mode that the app claims to yield a x1.5 speed increase (I have not tested it) with more token consumption.

Ah yes, I guess the portmanteau confused me and I assumed they were talking about "Ultra" the "reasoning effort" (which it isn't), rather than the "fast mode" which supposedly gives you priority over "non-fast mode requests". Although in practice, counter-intuitively, sometimes being in non-fast mode gives you faster replies than fast-mode, haven't got a feeling for why/when though.