Fwiw, thought I'd share that finally had the chance to hunker down this past weekend, having the house to myself, to finally drill down into the power distributor filter options (all had been thoroughly broken in) as well as the xdms sound profile (alt vs default) and xdms driver options. Also reconfirmed rolling of around 20 tubes w/ the Horizon.
It was an enjoyable process and feel at peace with a combo that works best in my system (w options currently available) and a complementary tube set.
Using the order Emile recommended, I started by experimenting with filter combinations of the power distributor. For me, the changes were not huge (less than changing a pair of triodes in the Horizon, for example) but settled on default/default for both switch and router. In the end, I wasn't searching for specific sound characteristics, but I felt the def/def combo was the most engaging, tonally balanced and transparent.
On current version of sound profile in xdms (alt vs default), again not a huge difference but default prevailed again. Finally, I continue to prefer X1. Again, for engagement, transparency and, specifically, the gorgeously impactful and layered bass.
Can finally sleep peacefully knowing I have squeezed out, at least for the moment, the best sound parameters I can get here. Very pleased, content and excited for what is to come. Thank you Taiko team!