Okay - you haven’t got much time to think about this then (unfortunately).
If you are not going to get commercial litigation experience during your TC, it will be very difficult to qualify into that area.
Given this, I think you have to consider carefully:
1) is this interest in commercial litigation genuine? (You said you think you may be interested - it might be worthwhile exploring that further so you are more certain either way)
2) what is your priority? Qualifying or doing commercial litigation? It sounds like you most likely won’t be able to do both.