How desirable is the separation of beacon blocks from execution payloads w/o the other guarantees that epbs has been associated with? (unconditional payment, builder protection w/o relay) How much value do we get just by ensuring that an execution failure still leaves a valid beacon block?

Does having execution payload be separate from beacon blocks imply that even if two different clients execute the payload differently, they can still reach consensus on the same beacon block? If so seems like this is quite nice for maintaining liveness even in short run client failures

mmm I think it doesn't quite get you that, because each client would still be convinced of its own assessment of the payload. E.g. if geth thinks a payload is valid but no one else does, all validators running geth will just continue undisturbed, while others will see the beacon block as canonical but not the payload