Despite the CRC errors (I guess ES didn't exceed DLM profile's threshold, alledgedly 2880 ES in a 24 hour period if on 'speed' profile, according to Zen), my connection remains on fastpath but has been speed banded from 74/20 to 49/15 presumably due to all the re-syncs I had in the early hours of the morning on version 2072.
Version 693 is so far the only stable version, although some CRC's still occur I imagine ES is below the threshold. I sure wish I could know what the ECI /r measures in CRC errors but I doubt I ever will due to the unreliability of the statistics on that modem. I know the HG612 produces a similar CRC rate to the ASUS DSL-AC68U (a regular 1-2 CRC errors per minute or two, with a rare occasional burst of 10-20 CRC's - on the downstream) when I had it plugged in.
When my connection speed returns to normal, if it does (as it's definitely way below the estimated speeds now), then I will try versions 2048, 2049 and 2050 to see if they perform differently with the exact settings I'm using at the moment.
EDIT 1
Decided to try version 2050, so far so good. It has held for over 2 hours though a similar 'trickle' of downstream CRC's exist still.
I think I might write a very basic app to measure the possible ES and the CRC rate, perhaps by a graph too. Best way I think is to use telnet and read the info_adsl.txt file in the /tmp/adsl/ directory, every second or two if possible.
Current Settings
	
	
	
		Code:
	
	
		DSL modulation:					VDSL
Annex mode:					Annex A
Stability Adjustment (ADSL):			Disabled
Stability Adjustment (VDSL):			Disabled
Tx Power Control (VDSL):			Disabled
Rx AGC GAIN Adjustment (VDSL):			Stable
UPBO - upstream power back off (VDSL):		Auto
SRA (Seamless Rate Adaptation):			Disabled (BT doesn't support this yet anyway, as far as I know)
Bitswap:					Enabled
VDSL Profile:					Multimode 17a
Improved Impulse Noise Protection (G.998.4):	Enabled
	 
 
EDIT 2
Over 6 hours uptime on version 2050, 377 CRC errors, I'd guestimate ES is somewhere between 200 to 300.