If possible I'd modify the 30 amp outlet on the parallel cables..
Or use the bypass.. Question.. Will the bypass reset when power is removed (I believe it will)
The Power Gard (Surge guard) monitors frequency and voltage, So do the Honda inverter generators. if the frequency goes wonkey they tend to catch fire. thus they lock to each other and to the crystal controlled time base, They are, more "Paranoid" of frequency errors than your surge guard and for very good reason.
Likewise if the voltage drops it tends to drop all the way to ZERO, (or if it climbs) NOTE this is not true of some of the china knockoffs.. But it is for Honda (And, though not as well ONAN RV generators), they perform all the functions of the Surge Guard and do it well.
Most other brands I do not know about (I know one Chinese brand that had over voltage issues.. but I'll not name it).
Now: here is a question for folks: WHY do we use a safety ground (And yes, I know the answer).