Connencting Gallo 3.1's and SA amp in HT

Recently purchased a 9.2 Onkyo TX-NR1007 for use as a preamp and surround channel amplifier in HT. Currently using Gallo SA and Parasound HCA 1200 amps for the Gallo 3.1's and no dedicated sub (4.0 mode). What are the best receiver settings to use and also which pre-outs should be used for the SA / sub-in connection on the 3.1's

The Onkyo allows for adjustable LFE levels and the option to send both LFE and L/R data out the sub pre-outs.

Should I set the Gallo SA cut off at 100 HZ and let the Onkyo do its RC, sending the .2 data out the sub pre-outs to the SA? I could also set "double bass" on and LFE effects off when listening to 2 channel music or both on for additional L/R low end bass for HT

I suspect setting the XO on the SA to 40-50 HZ and tuning it for the best 2-channel music response would be best as that is my priority. One disadvantage in this scenario is that HT listening now has LFE and RC with less bandwidth to operate over on the 2nd voice coil diminishing the effect of dual subwoofer HT. Theoretically I should be able to raise the XO of the SA to 100ish, let RC flatten the room response and both HT and 2 channel music would sound great, but I have read pure or dierct mode sounds better than the Audyssey for 2 channel.

Is sending the L/R data out the sub-preouts to the SA better since I would have to use a Y cable if the SA was to be connected directly along with the Parasound to the single set of L/R preouts from the Onkyo. Any advantage/disadvantage on which preouts to be used?

Is mixing L/R data and .2 data in the same woofer via the dual voice coil a bad thing? I read somewhere that is not a THX config.

Obviously, continuously adjusting the SA crossover between HT and music listening sessions is not a desirable option.

Gallo w/ SA owners and HT buffs weigh in please!