EMR, I'm using the HH for SRT on my XTC fire (sheesh acronyms!)
I do notice it flattens in shape by the end of the job, gotten used to it now. I don't have any splices, which is no problem with SRT, but even using my Hitch Climber with a knot, it was ok.
What I did do was stitch a loop on one end to tie my throwline onto so pulling up there would be less chance of it snagging on anything.
I have a length of Tachyon in Bermuda, but did not get the chance to try SRT on it before I left last time, this year the HH will come with me so I'll be able to compare, I'm anticipating a few adjustments due to the Tachyon being a bit skinnier.