I'd tend to disagree there, 1ev is double or half the light which is a lot.
Yes, but that comes at the cost of 4EV of aliased highlights at 100/1600, or 6EV at 100/6400.
And I somehow doubt the shadows at ISO 100/1600 will actually look cleaner than at ISO 100, because of the half resolution (which, in theory, reduces the DR by 0.5 stops and also affects the noise structure). So, without seeing the images, I'd say the tradeoff may not worth the extra effort.
If we have a bracketed image set, one at ISO 100 and another at ISO 1600, we can simulate a dual ISO image (lookup fake_dual_iso.exe) and see exactly if there is any extra shadow detail or not, compared to ISO 100.
Anyway, I guess either the current dual_iso code works with the 80d or it doesn't b/c Canon has done some radical changes ...
The CMOS registers are still used (strings are present), the implementation appears to have changed (strings look different), but ADTG strings are no longer there. Interesting that 5D4 contains ADTG strings on the AE processor, but none of them is present on the main procesor.
Some interesting strings from 80D, not present on earlier cameras (not even on 750D/760D):
( pCmosGain & CMOS_ADDR_MASK ) == CMOS_REG_R_GAIN9
( pCmosGain & CMOS_ADDR_MASK ) == CMOS_REG_R_GAIN10
( pCmosGain & CMOS_ADDR_MASK ) == CMOS_REG_R_GAIN11
( pCmosGain & CMOS_ADDR_MASK ) == CMOS_REG_R_GAIN12
(R_GAIN9_Param & CMOS_ADDR_MASK ) == CMOS_REG_R_GAIN9
(R_GAIN10_Param & CMOS_ADDR_MASK ) == CMOS_REG_R_GAIN10
(R_GAIN11_Param & CMOS_ADDR_MASK ) == CMOS_REG_R_GAIN11
(R_GAIN12_Param & CMOS_ADDR_MASK ) == CMOS_REG_R_GAIN12
Some strings from 750D/760D, not present in 80D:
( *pwRegister & 0xF000 ) == CMOS_VSKIP_START_ADDRESS
( *pwRegister & 0xF000 ) == CMOS_VSKIP_END_ADDRESS
( *pwRegister & 0xF000 ) == CMOS_HSKIP_ADDRESS
( *pwRegister & 0xF000 ) == CMOS_SAF_RESET_ADDRESS
[REG] @@@@@@@@@@@@ Start ADTGDMA[CS:%lx:%lx]size:%d
So, dual iso will probably work, maybe not out of the box, and there appears to be some potential for tweaking the gains.
However, at this point, it's just speculation. As in...