According to @deanmlittle, permissioned Solana instructions can branch by checking the first 8 bytes of the pubkey of the first account and assigning a different signer for each instruction, with an overhead of only 2 CU per instruction that would be spent anyway, which is directly relevant to execution cost tracking for traders and developers monitoring Solana program performance, source: @deanmlittle on X, 2025-09-03.