Marked as Concert & Recording, Simon Callaghan's schedule for June 27th, 2021 has Rubbra's (1st) Piano Concerto in A minor with BBC National Orchestra of Wales and Martyn Brabbins. I believe this work was discussed somewhere here earlier.
According to the late Colin Seamarks (possibly misremembered personal communication) I think this was the one Rubbra work that really tried out twelve-tone techniques; might turn out to be outside the remit unfortunately (though I've been intrigued and would like to hear it. I adore Rubbra anyway...)
I will ask Mr. Callaghan about this and get back to you.
Simon, who is currently typesetting the MS (which, he says, is very messy) describes the work as: "Quite a big orchestration, very romantic in style, lots of virtuosity..."
That's sounds promising. Seems Mr. Seamarks was mistaken.
Or could be I misremembered and he was referring to a different work. Sorry!