I have used a few other light shafts that have been able to handle the same swings so far without issue. Diamana ZF 40x, Aldila Rogue Elite Blue 55x, Ventus Black 5x, Tensei Blue 55x.
Updating myself - the grip came off after a few months and back to the pistolero. I couldn't get over the feel. I don't think I'm as bothered when putting with a SS 1.0 Pistol which is similar construction but it is smaller than the Reverse Taper. I had some of my better putting rounds with the reverse taper pistol but the feel was too much. Now I lock the pistolero into my lifeline for consistency and get the feel back.
Not to be a party pooper but I played an Avalon 5 TS for a few months in my driver. 110mph Club Head Speed and it ended up snapping over by back on a mild swing. I thought it performed pretty well but not sure how high quality the graphite used is.