Parallel loop is also set for +4 dbu. Thing is with pedals you can clip your pedal's circuitry and its buffer circuit (if any). BTW what is your reverb tank? Also the make and model of your delay and chorus. Some can take +4 dbu. Stomp boxes typically don't.
Mr. Scary is more Marshall/Soldano tone. Grail is Mesa DR. Love Mr. Scary. Don't like Grail that much. Grail is better for rhythm tones IMO. Mr. Scary for leads. I think Grail snags Lynch's "Tooth and Nail" tone, while Mr. Scary snags the Lynch Mob stuff.
I'm using a KH-1 for clean, Brahma for vintage crunch, and Mr. Scary for lead channel. KH-1 is a very nice clean, but because it's so clean I need a compressor/limiter in the FX loop so I don't clip my multi-fx unit (Lexicon MX300), and with it I have my Fender Twin clean.
Brahma can go either rhythm or lead -- it's toned after a Marshall Super Lead. Takes overdrive pedals and treble boosters very well. Very versatile.
Mr. Scary is a lead tone somewhere between a JCM800 and Soldano SLO.