I primarily play 7 strings (in A) but I do also occasionally play an 8. I use the same patches for both.
Over the last year or so, I've had to turn up poweramp hardness in the advanced menu to get the tightness I like, otherwise things get too flubby. The poweramp hardness thing is like a cheat code for tight tone in my opinion. You can make the Recto models razor-tight in this manner.
Keep an eye on the master volume as well, too high settings distort the poweramp too much and get flubby and indistinct. For the rectos as an example, I usually have the master between 1 and 1.5. But I like a clean poweramp so your milage may vary. Many high gain models I like around 2 to 3 at the absolute maximum, but some can tolerate much higher settings.
I also am not a huge fan of the in-built boosts, I prefer using external ones. Also it's more fun for me to be twisting real knobs. I do like using the FET Preamp model though, with drive at 0, level at 10, and then using the 3-band eq in the pedal to adjust how tight I want the tone. Usually I just put the bass all the way down, and go from there. Add the 'cut' setting in the amp block if I want it even tighter, or stack with a PEQ using just a high pass filter.
A bump using the PEQ at 1400 hz to 2000 hz (in front of the amp) can also add some clarity and attack. Sweep it around to find the frequency you like.
You can also do this in the drive model, set the mid freq at like 1600 hz or something, and turn up mids.