The installer is talking crap. Best find another installer. This guy's knowledge seems very limited. Either that or he has a load of Unicable 1 LNBs he is trying to off load. Either way, steer well clear.
Both Abu and I have Solo4K receivers. In Abu's case he has Unicable LNB to tuner A and a motor on tuner B. The six link tuners (C through H) are chained to tuner A and using the Unicable LNB on 28.2E. The Unicable side of my system is set up the same.
I can't see why anyone would recommend the Unicable 1 LNB for the Solo4K as that would limit it to recording from a maximum of 4 transport streams, not 8.
Having a 32 channel LNB means you can have the Solo4K using 8 and still have plenty of extra SCRs for receivers in other rooms.