Corda Flow Responder counter party logic

Basically, i have initiating flow with state producing transaction, involving 3 parties:

PartyA - ourIdentity
PartyB - should sign
PartyC - should sign

Initiating flow creates new state and builds transaction, then collects signatures from other parties.

PartyB and PartyC should make own specific business logic verification.
Will it be correct to place those checks in flow responder, if not - where to place them?
Also, can i separate responder code like:

override fun call(): SignedTransaction {
    val signTransactionFlow = object : SignTransactionFlow(otherPartySession) {
        override fun checkTransaction(stx: SignedTransaction) = requireThat {
            val output = stx.tx.outputs.single().data
            
            if (otherPartySession.counterParty == output.participantB) {
               // Do checks for PartyB
            }
            
            if (otherPartySession.counterParty == output.participantC) {
               // Do checks for PartyC
            }
        }
    }
    val txId = subFlow(signTransactionFlow).id

    return subFlow(ReceiveFinalityFlow(otherPartySession, expectedTxId = txId))
}