SET - Limitations from Amp, Speaker Match, Both?

Considering diving into the lower-powered tube world for a second system -- amplifier and tube compliment far from decided at this point, but let's assume the world of the 45 and 2a3 for sake of argument.

I obviously have little listening experience with the low-powered tube amplifier world as well as SETs specifically.

I have read of the enjoyment folks have had.

I have also read of many limitations, some in extension, some in detail, some in dynamics, all from various angles and system configurations.

Let's assume a relatively popular 45 or 2a3 amplifier, exotic parts, but no exotic topology or anything, paired with what would be considered an ideal speaker for it -- no crossover, extremely high sensitivity, and an extremely easy load that matched the amplifier as perfectly as you could come by.

Let's also assume that we're working with a speaker that doesn't go extremely low -- let's say its +/- 3db point is 30hz or 40hz or 50hz..

Eliminating much of the typical issues of system matching, and assuming an ideal loudspeaker, what limitations remain?

With the right matching, is a 2a3 or 45 based amplifier suitable for all musical styles? A thriller of a movie, hard rock, techno, the sound of a chainsaw. These obviously aren't what I'll be listening to, but I'd prefer to choose extremes to truly understand what the end result is...

Are headroom and dynamics simply a function of the amplifier and speaker matching, or do limitations exist with a typical amplifier as well?

Just curious if in an absolutely ideal match of wattage/voltage and transducer, what limitations still exist.