Just a quick pointer on the D/D.
As you are only able to use your Gain on 0-2, I would suggest on 0 Gain it will allow you to use your D/D at 5-6 as it is not required too go so deep to knock out the smaller nail's (if by going deeper than required you will get a similar clogging as you would if you used too much gain, this is what causes the iffy signal's it'is because there is too much D/D going into the ground and not being allowed to be excepted because .Gain is either too low or too high to cater for the D/D.
What I would suggest is:
Gain set at 0 would require a D/D ot 4-6.
Gain set at 1 = D/D at 4-6.
Gain set at 1-2=D/D at 6-7.5 .
Gain set at 2-3 = D/D at 7-8.
Gain set higher than 4 will allow a D/D at 7-9, this is only possible if the ground will allow such Gain to be used.And depending on what you are hunting for.
All in all if the ground will not allow such D/D or gain too be used in sync back off either or both ( Gain + D/D too suit the condition.s.)
If you can plumb you Gain depth and D/D to or near equal too each other then you will have a different behaviour to the BLISS. If on Gain 4 for instance and the D/D is on 7 and you are still digging small nail's increase your D/D by a small amount untill it does knock out the nail's and no more.
If the D/D is clogging the target signal you are using too much for the depth being achieved , it's just a case of understanding this and you will be up and running.
Also I did notice in one of your video's that you used the auto zones Toggle (zone I) to manually ground balance.
This is not possible, as the auto zones is solely for Auto G/B. too Manually G/B you will need to use the Ground rudely and Ground finely control's.
I shall be making a complete run down on the setting's and uses of the BLISS on video once I have recovered enough to do so.
Meanwhile I hope this of help.