Granted, things may, and sometimes must, be done slightly differently to accommodate a shooter. But closing one eye is not, at any class, competition or military instruction, taught as "correct".
Hmm. Coulda sworn we were taught to shoot with just one eye open in the Air Force, but it has been 12 years since, so it may just be that it's a fuzzy detail of a memory... I
know we were taught to shoot that way at an academy I attended much more recently.
Anyway, let's get back to the OP's issue. What I was or wasn't taught isn't important right now.
Trying to figure out if I need to continue working with both eyes open and hope one day I can get it or go ahead and make the transition to one eyed shooting while on the move.
How do you view IDPA? (1) There are some guys who shoot IDPA in their carry stuff exclusively, use the same mouse gun they carry daily, dress as they would on any normal day, etc. They view IDPA as a way to practice for a real SD scenario. (2) Other guys use OWB holsters, larger guns than they would ever try to carry on a normal day, etc - to give them an edge in the game. Nothing wrong with that. They view IDPA as a sport, as entertainment. In it to win it, etc.
Where do you line up? Do you conceal carry at all, or is that something you don't worry about? Do you view IDPA as a sport you play for fun, or as an opportunity to practice in your normal EDC gear, to prepare for that day where you may need to defend yourself?
If you're one of the Option #1 guys, you may want to continue trying to learn to shoot both eyes open. After all, based on your perspective of the game, it doesn't matter if you come in dead last every time, as long as you're growing personally. If you're an Option #2 guy, stop limiting your ability to perform and just do what works best for you.
Ultimately - and this is true no matter what you think of IDPA, or what you decide to do - it doesn't matter what the "right" or "correct" way to shoot is. This isn't a test in school where you have to use a #2 pencil and fill the bubbles in just right. Just do what works best for you. If that means you make modifications to your style, great, as long as it benefits
you, and you aren't being unsafe or hurting anyone by doing it.