I quite liked it and I don't think anything Blaxill did affected the ratings in a negative way. It was stiill averaging 6.5-7 million viewers before they moved it, and then it was consistently below 5 million. Amazing really how badly the Friday move hurt it.
I remember in this period that pretty much every time the show wasn't on opposite Coronation Street, the ratings went up - certainly one of the few times I remember it getting into Broadcast's Top 70 of the week was during the 1998 World Cup when it was on at, surprise, 7pm on Thursday. Which suggests that however many revamps they did of it, the only revamp that would have had any effect would have been a crap revamp of Corrie.
On two occasions in 1997, when the regular slot was unavailable, it was on BBC2, but at 6.25 after The Simpsons, which perhaps wasn't a bad idea, it had a good lead-in and was in a slot where the target audience were regularly watching. Perhaps a shame they didn't do that more often when they had to move it. One benefit of the Friday slot in the early days was that there'd be a nice flow from BBC2, circa 1998 we would watch The Simpsons and Robot Wars until 7.30, and then switch over to Pops, and that worked quite well. But in later years that BBC2 slot deteriorated and it became increasingly adrift in the schedules, I remember in 2003 it was preceded for several months by Open All Hours repeats, which is hardly the most appropriate lead-in.
According to the Kaleidoscope book, it did get an airing on TOTP Plus on UK Play in January. They did two or three editions of that every week - it was basically clips of recent TOTP performances of songs still in the top 40.
I have this book, I bought it about a decade ago (I remember it was on Amazon a few years later for a ludicrous price) and at the time it was absolutely fascinating, although these days there's probably less info in there than you'll find on the episode guides on Popscene. Essentially it's a running order for every episode of Pops but as you say, circa 1998 it starts including all ten million episodes of Top of the Pops Plus, making it virtually impossible to navigate. And it's clearly from someone's personal database which they haven't bothered to edit, so there are comments alongside some of them like "tape runs out after Queen", "breakup of satellite signal halfway through" and even "we were in the audience for this one and we rocked!".