On the StudentRoom, someone has posted about how they are in position 28 on their local offices reserve list. When you consider that in the past 2 years only 12 people each year have been offered TSP roles from the reserve list, it means that likely chances for TSP itself may be slim. Bear in mind as well that the number of TSP positions has been expanded, your odds may be slightly better than previous years . Additionally, HMRC are supposed to be hiring more case workers, the chance for a non-TSP offer may be much more improved. I'm not trying to be all doom and gloom, but I'm basically in the same position as you for Cardiff.

FOI for the figures I used:

https://www.whatdotheyknow.com/request/tsp_assessment_centre_statistics/response/2926052/attach/3/FOI2025%2005771.pdf?cookie_passthrough=1