My Super Grafx w/ Super CD-Rom unit was the LONGEST system EVER. With that rig, I had to run the AC adapter for both. I regret selling them in 1999
I would use the male/male piece with the CG II. In 97-ish when LT's were found minty for around $300, a friend of mine ran an LT and Interface unit with two AC adapters as well (one for LT and one for CD-Rom) since the LT screen is power hungry.
We never toyed with hooking his LT up to my SCD unit because we didn't have the LT adapter nor the RAU-30.
FYI, if anyone is ever interested in parting with a fully functioning LT, hit me up. Still regretting not picking up an LT in the Turbo Mailing List back in the mid-90's...