>> But, none seem to offer much in the way of a little bit of height
I think you need to specify the specific maximum height you are looking for.
The Sirui you mention has an 11" folded length, 5 sections, and an upper leg diameter of 22mm.
In order extend it only a modest amount you are surely down to some very skinny legs. It is difficult to even speculate on the diameter of the lowest legs but I have seen similar tripods in big box stores. Fully extended they literally wave about, for quite some time, with just a slight push on the mount. The bottom legs are literally pencil thin, or likely thinner.
I would also do some research on the inner leg diameters in order to get some sense of the stability (or lack of).
Yes, you will not have to deal with a mirror, which affects every shot. But you should consider the conditions you will shoot in- especially wind, and the shutter speeds.
I have never seen a Sirui tripod so I have no specific opinions on them. I do know that I have never seen a $130 CF tripod that I would use- for anything - certainly not well extended. And I have seen a few, usually in big box stores like Best Buy.