I have not tested the KR T-100 in the LIO DHT PRE or L2 Signature Preamp yet.
The filament requirement of 5V, 2A is no problem. You would use the 5V setting on the filament switches.
Looking at the data of this tube on the KR site, it appears it should work fine. But I don't want to recommend
it until I first test it on the bench and carefully listen to it.
1) Has anyone compared any of these tubes in the LIO
This is a good way to ask the question, because feedback from those who heard these tubes in a different component
(e.g. Lampi dac) may not be helpful in detailing how they compare in a different circuit such as the LIO DHT PRE, and
I'll be doing more DHT comparisons this fall, and plan to bring a few different ones to RMAF in October.