Split/Fluid-S systems: A 3-way split

I know there are some systems where the marking of the argument of an
intransitive verb can be accusative or ergative based on volition. I
also know in some languages some experiencers can appear as datives
(although I don't know of any language where this is systematic), eg

to me see her = I see her

 If you put all experiencers in the dative case, then (I think) this
would include the arguments of most stative verbs (eg to be red, to be
ill, ...) wouldn't it? So you could get a three way instead of two way
split in intransitives:

stative verbs/verbs with experiencer as single argument (argument in
dative case)
active verbs when action is volitional (argument in nom/erg case)
active verbs when action isn't volitional (argument in acc/abs case)

 Do you think this is a realistic system? I'm thinking about doing it in
a conlang. :)

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