I thought about this. It wouldn’t work for Star Pact I don’t think because you’d need sufficient attack speed to generate and then channel before the meteor lands.
Could be more interesting for Meteor Shower or other Etched Sigil builds that don’t involve manual skill casts.
However, while Etched Sigil can proc up to once per second, it will only proc on a tick of a channel skill. Lower attack speed lowers the tick rate. You don’t want tick rate lower than 60 fpt, otherwise you’ll be losing out on Etched Sigil procs, because you’ll have less than one tick per second so can’t get Sigil procs until the next tick happens.
While Etched Sigil proc rate doesn’t really scale with attack speed, there IS such a thing as too little attack speed.
With Arcane Torrent, If you have any less than 0.33 APS, that will drop the tick rate under 60 fpt.
At 0.1653 APS, you’ll only have a Sigil proc per every 2 seconds. At 0.1105 APS, you’ll only have a Sigil proc every 3 seconds.
The other interesting scenario will be APS snapshotting for channel skills. I’m not an expert on this, but I’m pretty sure some channel skills snapshot your APS when you start channeling. That seems to be a key component of Rapid Fire pushes. So you could snapshot your higher APS before Stone Guantlets kick in, then just never stop channeling. I don’t really like that though, I think it’s a bit of an abuse of the intended mechanics. I thought they fixed the APS snapshotting with most skills, so Rapid Fire may be the exception. Not sure.
sVr also opened up the possibility of CC immunity preventing the attack speed debuff: Full Mechanics of new Legendary Affixes incl. Bugs and a QoL changes
If they implement that, that opens up a lot more options.