Ele3 Chrono3 here. We’re pretty much in the same boat except that I went full CON instead (don’t mind it, just for lols).
A non-SPR Chrono3 doesn’t get much except for Pass, Slow, Stop and Backmasking.
I took Quicken to lv.2 for 100% uptime w/ Crit Rate attribute at zero SPR investment. I only use it when supporting during WB and during damage check floors (1st, 4th, 5th) in Solmiki runs. The ASPD boost is bad compared to a high/full SPR build but it’s better than nothing especially during “destroy X” stages.
Still had to max Haste to get every point of movespeed possible even without SPR. Do note that with a full/high SPR build you can get twice if not more than when you didn’t put points in SPR at all. I think I get around only +8 movespeed at lv.15.
Here’s how my distribution looks:
Reincarnate - keep it at lv.1. It rarely succeeds, and 6 seconds is more than enough time as long as you get used to timing it right before your party kills the boss. Everyone has different “proven” methods to proc Reincarnate (e.g. must stand and face boss when casting; must face boss and jump when casting; etc.) so feel free to experiment. I’ve had success with just standing in front, facing/targeting the boss then casting it.
Slow - it’s a pretty good CC. Didn’t pay much attention about how it affects boss but I think it does as it would normal mobs.
Backmasking - keep it at lv.1. You’ll only be using it as a backup Resu. Not sure about it reviving non-pt members.
Stop - like Slow this one’s a really good CC too. If I had more points I would’ve maxed it. You can toggle the “Stop boss” attribute on and off if needed (e.g. in Solmiki boss stages you can turn it off so that only the boss minions are affected and your pt can keep on damaging the boss).
I’m not sure where to put the 1 extra point (even to this day) so it’s up to you.