The main, prime, and simple point of this thread and the reasons not to use ROM manager, can be summed up rather simply as follows: given what you've said about ROM Manager - being able to perform something only after it has been done - still makes downloading and using ROM Manager completely pointless. It will brick the Optimus Elite as no, in fact, it is not correctly supported, or there wouldn't be an issue in the first place - the proper checks, coding, etc., would be in place to be able to successfully install CWM when it hasn't existed before, detect and repair a broken/corrupted version of it, and/or update it, all without bricking your phone, and all being able to be done on the first try. Downloading ROM Manager to install an outdated version of something we already have, is likewise pointless. Downloading it to install what we have working, when what it installs and how it installs it does not work without what it's trying to install having already been installed, is pointless. ROM Manager has a few things that do work for the Optimus Elite. If the Optimus Elite were properly, correctly, and completely supported, everything would/show work correctly, not only some of the extra features while the basics are broken. So, no matter what, using ROM Manager is completely pointless both for installing CWM for the Optimus Elite, for numerous reasons some of which listed above and are well-known and documented in these forums, as well as installing ROMs for the Optimus Elite as, to my knowledge, none of the ROMs for the Optimus Elite are available through ROM Manager either.
TL;DR, if you're going to use ROM Manager for either installing CWM or a ROM, for the Optimus Elite, you're either 1) going to go home disappointed, 2) wasting your time, or 3) going to brick your device. If you're using it for other things, who knows. Couldn't really be any clearer.