If you already have your results, you should be able to negotiate entry into any particular university that you like.
It sounds like you are doing the whole UCAS apply 5, wait, offer, wait etc [whilst UCAS works, it is partly designed for ‘local’ students who don’t yet have their final results]
there are other routes , here from Brighton (a bit lower in mystic prestige than your list)
“Full-time undergraduate degree courses
For most full-time undergraduate degrees you should apply to UCAS. However, if you already know that you want to study at Brighton, and do not intend to apply to other institutions then you should apply direct to us using our online application system”
and similar from Oxford Brookes “International students, For September entry, applications can either be made directly to the University or through UCAS. For January entry, you will need to make a direct application to the University”
But you’ve chosen the UCAS route which is fine! I’m sure you’ll get offers & mutually be satisfied.
If you don’t get offers, then feel free to phone up a single university at a time, Nottingham, Manchester etc and ask them about using the 'record of prior acceptance' as part of Clearing (in June/July/August 2021, for last minute start in September/October 2021)