I’m assuming you’re talking about the Funsr1 2.0 with a twist. Most of the DIY products sold in the community usually have decent tech support from the sellers, as well as random people that might know what to do.
Mount is always good, not having to hold the device and keeping it in place and just letting the machine do the work is great. That’s why most people suggest a handsfree option for devices. TheHandy in particular is not particularly great handheld since its awkward to hold.
Twist seems like a gimmick but there’s a reason that its the upgrade that people want for single-axis strokers the most. At this point, single-axis designs have been locked down and there’s not much else you can do with just the up/down stroke since any more degrees of movement takes you into multi-axis. Adding the twist axis is next logical conclusion if you dont want to add more arms. The next design from Tempest is literally just adding a twist-axis to his single-axis stroker: SSR2 Alpha
The best use for it is for blowjob/handjob to add a spinning motion on strokes. Having it twist in one direction on a down stroke, then spin the other way back up is a new sensation that you can’t get from normal devices. You can also just have it twist back and forth for teasing if someone designs a script for it. Worst case scenario you turn single-axis scripts into two-axis by linking the strokes up and down with specific spin directions.
Honestly rather than it be a useless gimmick, some people find it to be too much at times since it gets intense with the twist, so its an optional upgrade for multi-axis devices.