Like Colin, I use the dash mounted trip mileometer (A&B) resetting them in turn every time a regen occurs. Mine are normally around 514 miles apart. However, I have stopped worrying about changing my driving style when a regen has started and just drive normally. This could be in start stop traffic or on a run. I have found that in normal traffic conditions, a regen completes in around 6 miles whereas on the motorway, it can take between 15-20 miles. I always make sure they complete (instant consumption goes back to 999.99 coasting) and have never had a warning light come on.
So whilst they are a pain in the a*^e and knacker fuel consumption, they can be managed quite easily.
2013 SE Nav 184 Auto (now deceased)