Can I apply for clearing with a firm choice selected?

Hi there, when I went to college in 2016 I started a L3 Creative Media Ext. Diploma. I finished this course in 2018 with a grade Distinction, but I changed my mind in my career path as I wanted to become an architect (very different, I know). My teachers told me I couldn't get in on my diploma so they told me to apply to A levels; bit annoying as I have the skills, just no qualifications to prove it.

Anyway, I was in my first year of A levels and then found out I could infact get onto Architecture courses using my diploma (go figure) so I applied to five and got accepted into two with unconditional offers (as I've already done the course). London Southbank Uni (my initial first choice) and Southampton Solent Uni. I got rejected from the University of Reading, which I've now ended up liking more than Southbank and want to try and get in through clearing, but I need to pick a firm choice by May and I don't want to be in a position where I might not go to uni at all.

So, my question is, can I apply for clearing for Reading while still having a firm choice or do I need to risk it for the biscuit and hope clearing works out?

Why do you think Reading would change their mind about you?

At LSBU the interview was 1 on 1, but at Reading it was group interviews. 1 on 1 I was able to talk about my ideas and plans. I had a whole business pitch about how I would use my degree to better society in terms of a solution to the affordable housing crisis in London. The interview was only supposed to last 20 minutes, we were talking for an hour and a half. In the group interview, everyone was asked the same 3 questions, we were only allowed to summarise in a couple sentences, then everyone showed a couple examples from their portfolio (he asked for the piece we found most challenging and a piece we thought had a deeper meaning to it) and there was a 30 minute time period in which to do this. There isn't a single change in hell you can grasp a student's potential from a generic and strict interview formula. If the university is as good as some of its students, I'd expect them to realise that.

My point is that Reading have assessed your application once and rejected you. Given that clearing generally consists of you phoning up and asking about places then there will be little chance for you to impress them.

Yeah that's true. What do you think my chances are of requesting and being granted a 1 to 1 interview? Does that even happen? Would that even further reduce my chances of reconsideration at clearing?