Thanks very much for your reply. Here are a number of things I think would fix a number of the issues I have (and I assume others have too).
1. The first is that having a minimum purchase of £5 is OK but it means in my case I need to choose at least 60 Match Odds matches. At first I only wanted to try it and choosing 60 markets was very time consuming and I gave up. I don't think there should be a minimum amount unless that's imposed by Betfair which is stupid in the extreme. I quite understand that Betfair are often stupid however. Speak to your API manager if that is the case and tell them from me it's stupid, lol.
2. I only need Match odds for the games I'm interested in, so I think some Filtration of markets would help a lot. For instance in the Doha ATP tournament at the moment I wouldn't mind taking a number of matches I wasn't that interested in if I could at least guarantee getting the matches I needed. If I could filter like All Match Odds for Round One that would be fine, or All Set Betting for Doha Round Two. You get the idea. Or if I could filter for all matches for Player X for dates between Jan 1 to Feb 1 2022. Filtering up front would help a great deal.
3. To have to confirm each single market you choose is really tedious and you could do away with that step imo.
However, the biggest single factor that would speed up the process is to allow the user to pre filter the data towards what he needs before choosing each market. I hope that all makes sense