I would use a combination of both a hitoverride and reversaldef that leads into a changestate that both go into the explosive state to be extra sure since authors tend to alternate between projectile SCTRLs and helper projectiles.
Sort of, I don't think it should matter whether it's a projectile sctrl or a helper projectile, because the P in the attr of the hitdef should be parsed the same way a projectile sctrl should. I mean, I didn't code the source (but I think helper projectiles are easier to code), but it seems like the proj. sctrl is just a way to remove the need for a helper.
The docs put it like this
The Projectile controller takes all the parameters of the HitDef controller, which control the HitDef for the projectile.
If I code my helper like this:
[statedef 1000]
type = S
movetype = A
physics = S
juggle = 0
ctrl = 0
velset = 0,0
anim = 1000
[State 0, helper]
type = helper
triggerall = numhelper(1001) != 1
trigger1 = animelem = 7
ID = 1001
stateno = 1001
pos = 70,-65
postype = P1 ;P2, Front, Back, Left, Right
supermovetime = 0
pausemovetime = 0
persistent = 0
[State 1000, 3]
type = ChangeState
trigger1 = AnimTime = 0
value = 0
ctrl = 1
[statedef 1001]
movetype = A
physics = N
ctrl = 0
anim = 1001
sprpriority = 7
...
[State 0, HitDef]
type = HitDef
trigger1 = animelem = 6
attr = S,SP ;SCA,NA,SA,HA,NP,SP,HP,NT,ST,HT
etc....
it will be parsed the same as one state with a projectile sctrl, down to parameters specified.
____
sorry i can't read my own writing
Use either hitoverride or reversaldef (I'd use hitoverride for what it's worth).