The Bosch charging system on our bikes, doesn't do a real good job of charging in slow speed, or stop and go traffic .
Could you explain the term current absorber, it's not a phrase I'm familiar with .
But from what you have said so far, I don't think there is a problem with your charging system, if you are getting 14.2 volts at 4000 rpm.
When I lived in Chicago, if I took my R65 to work, 5.5 miles, 14 stoplights, the battery would be worn down to where it wouldn't start the bike, in 5 or 6 work days.
You may need to put a battery tender, or charger on the bike, with your particular usage .