My preference: 1. 4-card raise. I think distinguishing between 3-card (cuebid) and 4-card (2NT) raises is more important than being able to show a natural 2NT, which can (with potential issues) go through double. 2. 4-card raise. Same reasons as (1) 3. 4-card raise. I like making very light 1-level overcalls, so there's little need for a natural 2NT. If I'm not playing xfer advances I like using this as a 4-card limit+ raise and the jump cue as a mixed raise. A non-jump cue would show only three card support. 4. 4-card raise. Same reasons as (2). 5. Natural. Here partner has shown a good hand, and we have few other invitational options. 6. Natural. Unlike (1) and (2), there's no other route to a natural 2NT here other than 'bid it now'