Well Ratty i was having the same problem as you.
i tend to know when mine is in regen with the 150 miles range as does it twice per tank and around town the gear change notifier on the display seems to be more sensitive
It could sometimes regen for about 30-45 miles
know i have got it down to an average of about 16 -20
How i do it now and tell me please if this is wrong, when in regen i tend to keep it at 2000 revs in 4th gear and sometimes 3rd gear when around town.
After about 15 miles i coast it in neutral for a couple of seconds to see if still in regen being near to the 1000rpm and if so i just floor the throttle around to 5000 and the regen finishes instantly. If it doesn’t I try again a mile or so later and then it always normally finishes on the second attempt.
if doing a regen just nearly by home i dont worry about it and for some reason when starting it up the next day i can finish the regen with just about another 8-10 miles doing it how i do it.
i was getting paranoid with it at first but this method really works and I don’t worry about it now,try it!!!!
Some people wont believe me but honestly works!!!
my only concern would be if it was harmful flooring it to 5000rpm for a split second????