I've understood that once a week psychotherapy is standard and many people consider the higher frequency acceptable only during crisis.

I personally have never gone that infrequently. The lowest frequency I have had is 2xweek and the normal frequency for me is 4xweek (psychoanalysis) and this without any ongoing crisis. I couldn't imagine that I could have gotten where I am right now by just going once a week - I think many deeper stuff would have remained quite inaccessible, or if it would have become accessible, the one week gap between the sessions would have made approaching this material too painful and thus perhaps impossible.

I realise that 4xweek is really out of the norm nowadays and many people could not afford it both time and money wise. However, I think that 2-3 sessions per week would be useful for many people to proceed more quickly in their therapy.

Could you ask your T to have more sessions per week?