I too have a Lune 253. I haven't used it in a few years much, but it is a very good quality reel. Congrats on your acquisition.
Yes, the braking system that is built into the spool is designed to help prevent back-lashes during the cast (i.e. mid flight). It does work, but it may limit the distance of the cast - although this shouldn't matter much for short distance casts. However, nothing beats thumb control. Once you become proficient casting with a levelwind and can master thumb control, you're set!
One thing about the Luna 253. I found that my anti-reverse clutch started failing. I would have to take it apart and clean it out, which would fix the problem. But after a few trips, I noticed it would fail again (when you have a coho on the line, this can be very irritating!).
Good luck with the reel. I hope this helps - not that I should know very much about baitcasters if you read my handle...LOL.