Hi Allison.
As per my initial post on this topic, I will answer yes *and* yes to your first sentence above - Both the stock internal lpf and an external filter for 28 MHz are deployed.
A single yes to sentences two & three above.
However, as to your sentence four above, I note that the datasheet for the 74ACT00N indicates that it possesses adequate drive current capability for Q1,Q2,Q3, with a maximum switching speed in the single digit ns range.
This is not to say that it was ever expected that the QCX-series should operate flawlessly in the near-low-vhf range of frequencies ie 10m band, for example.
I'm only saying that, with a little touch here and there, it is certainly possible to obtain *some* success there.
Tnx & 72 / 73,
Bill, N4QA
