The only hard part about threading 'lite' comments is a stable parent reference, but we could use the first 8-10 bits of the tx hash for this purpose. The main reason I suggested non-threaded was for simplicity. It may or may not make sense to bundle these with votes (i.e. a comment with a up/down vote) or reactions, and nesting them makes less sense in that case.
RE: Hive Communities: An Interview w/Steemit's Senior Product Engineer