To be honest I'm no expert on the possibilities so I'm not going to be able to answer that other than to maybe reach out to your HR people and ask for some details on what your options are. Or ask on r/UKPersonalFinance.

thesalarycalculator.co.uk is a good site if you wanna compare how different scenarios affect your take home pay. E.g. put your salary in with student loan ticked for plan 1 and your pension contributions at their current level, then note the take home pay per month. Then do the same but with student loan not ticked, to see how much that increases your take home. Then experiment with upping the pension contributions until the take home pay matches the value you were getting before you took the student loan off. That'll give you an idea of how much you can increase your pension contributions without noticing a difference in your monthly pay. Then head over to one of the various pension calculator sites (Aviva is decent and simple) and see how much bigger your pension pot could end up if you do that. Will probably be quite substantial!

I'm close to paying mine off so I will weigh in here.

Probably best to avoid "lifestyle creep", this is money you haven't had before now and it should probably be put straight into some investment, a stocks and shares ISA for example, or to overpay the mortgage (or save for deposit, so I guess that's LISA these days). I'm assuming since you're actually able to pay it off then you must be on decent money and you won't "need" the extra couple hundred quid a month.

Other thing to realise is that the 9% over whatever amount you've been paying back was after tax. So I think there's some decent argument to be made that you're leaving money on the table if you don't instead redirect a larger portion of your gross salary into your pension via salary sacrifice. Then instead of paying the tax man you instead significantly increase the contributions to your private pension.

I'm guessing the UK financial advice sub (or I guess "com" if there's one here on Lemmy, sorry, I'm new here) would be a good place to ask.

Jam Roly Poly with custard!

Only other things I can vividly remember were turkey twizzlers and luncheon meat - and I think I might've liked both of them...

This doesn't feel like an answer to the question. Sounds like you're saying that Android and iOS are both now similar, not that one has been victorious over the other.