Delegation is great but I don’t think we need an opcode for delegations specifically. We just need to let existing opcodes support delegations; for example, we could allow constructors to return eip-7702 delegations. I do support mutable code but I would prefer something more powerful like the SETCODE opcode (EIP-6913). Restricting mutable code to delegation is redundant with delegatecall proxies and is overly cautious.
I also think we should allow infinite redirects with delegation; they just need to be priced fairly.