You should drop that non sense about average pace, it is not good metric and it can serve only as cope out mechanism.huh? October? That 5 to 9 weeks away, they won't even get there, again, they aren't even fully over Novohrodivka. Again, after that, then what? Do you expect a complete collapse of Ukrainian front??
Again, if they are making 1000 meters before and now only making 1300 meters these 3 weeks, that's not a lot of gain in momentum (you are talking about 30% max).....You aren't talking about Russian suddenly made 2000 meters or 2.5km a week, that progress largely remain the same, the only different is Russia loses part of Kursk with it in the last 3 weeks.
I do not expect full collapse of UAF before Pokrovsk is conquered but after that Slavjansk and Kramatorsk are in cross hairs with favorable terrain conditions for superior force and if the uaf commit big numbers into defending those cities, collapse of whole their front is plausable.