haha MM, no harm with reading the advice twice!
Another thing that you need to consider as to when to take the UKCAT is whether they will take the BMAT too and if so when. Last year was the first time it could be taken early September, ie. before UCAS deadline. I don't think this was well known and didn't get that high take up (but maybe I'm wrong).
DD did take it then and did much better than expected. It has its benefits and disadvantage though. There is no flexibility with the test date unlike the UKCAT, so DD took it only 3 weeks after her UKCAT. She had not anticipated how drained she would feel after taking the UKCAT and found it very hard to switch to revising for the BMAT and indeed, hardly looked at it the first week. It's only afterwards that she admitted to me that she'd done limited revising for it. Whether she would have done better if taken in November, I'm not sure though. She was still in exam mode with the brain ticking and I think that compensated for the reduced revising.
The main benefit was of course that once she'd done it, it was all over and she could concentrate on her studies and preparing for interviews. In terms of whether it helps in terms of deciding whether to apply to a BMAT uni, I'm not. Going by tsr, most seem to have found it very hard this year and indeed, the average was lower than last year. It could therefore be counter-productive, resulting in opting out of a BMAT uni with competitive results.
But do not worry because according to a certain person on the other thread, all this consideration is just a waste of energy!