the way i understand it upheaval is effectively a mix of cadence and secondary effect mechanics like “Cadence with Explosive Strike” from fire strike
unsure of the exact details/interactions/what’s really going on, or how to label it better, but seems to be a relative apt description of how it behaves.
Every non wps strike with Upheaval enabled but not discharged is basically counted as Cadence does on the first 2 hits, then when a non wps crit occurs you get a Savagery hit that crits and a secondary hit that’s upheaval/when savagery crits it “discharges” an upheaval hit (which will then do its own crit check/wont default crit just because the sav hit critted), giving you 2 hits in a single attack, like fire strike and explosive strike (upheaval similarly then also being aoe)
the “every non wps hit is counted as upheaval/similar to cadence” is then also how we can get 2 devo procs to occur in a single attack despite not actually every triggering upheaval/an actual crit
i’m guessing upheaval acting that weird interaction way “sorta like a secondary effect mechanic” is why it would require direct Upheaval conversion or global conversion, similar to how Cadence conversion doesnt’ convert first 2 hits, or fire strike conversion doesnt’ also convert explosive strike/fire strike mod doesnt’ apply to explosive strike as it’s a secondary effect
quick demo
https://imgur.com/a/x9jB7Xx
edit, baboon that i am i didn’t show removing the upheaval points removes the lightning dmg present on clearly non upheaval triggered hits
non-upheaval upheaval lightning override https://imgur.com/a/yQP7u3H