The whole admissions system should have been frozen as soon as the exams were cancelled, and no-one allowed to 'hold' an offer - including those holding offers already.
Courses should have 'ended' as soon as Exams were cancelled and centres should have moved to producing grades based on performance. This would have eliminated 'variability' of teaching element. Uni's (and employers) would have known that all students were coming to them with 'incomplete' courses from this year, because all students in the country would have been in the same position.
Centres should then have submitted grades and these should have been checked at a centre level against prior attainment. If broadly in line (or if the cohort provably better/worse based on GCSE results etc) then CAG stand. Where not in line, centre should have been moderated accordingly, up or down across the centre/course. Centres should then have been sent the results, and been given a window to submit evidence to support those students who, again, provably, were likely to perform hugely better than in line with the centre.
The grade-spreads should then have been announced to Unis, giving them a real-time, known field for results across the country.
Unis could then have set their course entry requirements. Results announced UK wide on the same day, and 'admissions' opens. Students holding the needed grades all apply by a fixed deadline. Unis receive all Applications together with known results and start accepting based on the application, completing Zoom/in-person interviews/entry tests/ blah etc. If they've already interviewed and offered, Uni's have the option to re-offer on the same terms as before or not. All offers of places go out on the same day via UCAS and students accept/reject within a fixed period. At the end of the period, empty spaces go into clearing which runs just as it does now, with students having the option to stick/reject etc.
Effectively, the admissions process would have changed for everyone. The uncertainty would have been only in seeing what the course requirements were once the grades were announced, but it would have put EVERY student in the same position. Universities would have known the grade-spread ahead of time, and so could have 'adjusted' their required grades accordingly. Courses which are 'normally', say ABB, would look at the 'inflation' and set at AAB or even AAA so that they're still working with the same 'top whatever' percentage of students.
It wouldn't have been a perfect solution, but it would have naturally 'corrected' the over inflation issue for admission.