Does anyone recon that if i get to the gig and there still selling tickets (like better seats than the ones i have) that i would have a chance of just swapping them over?
I think ill give it a go,
you dont ask, you dont get

Give it a go by all means, but I can't see it happening. They exchanged the height warning tickets if you bought them before the warning was in place, but I had to first go through two levels of 'TM policy is that you got the best seats available at the time of buying and there are no exchanges or refunds'.

If you have tier 4 tickets and want to try this, phone them now and arrange to collect at the venue. The people at the venue will likely have zero negotiating authority.