but in saying all that i used to be a rock but have widen my game up now maybe a little too much which is why i post so my line check posts
It's fair enough widening up your game, but 3betting AJo OOP is going to get you in a lot of horrible spots.
Let's forget for a second you're playing a micro donkament, if you think you're ahead vs most players there's nothing wrong with flatting in this spot. By 3betting vs a good player when he's nearly 40bb deep he can 4bet shove almost ATC which causes you to think FML can I really call off here? Or he can flat and see an ace high board and get very aggro in a pot we've unnecessarily inflated pre.
Flatting the flop is just bad imo too. If the turn comes a Q or K you're going to hate it. He's already stuck 45% of his stack in, so cram it in his face. Better yet if you want to flat, just check the turn, it's the way ahead/way behind scenario in that spot as he almost never calls with worse and we can get him to bluff shove the turn and snap it off.
I'm also very surprised you think micro donkament players are 4bet shoving light. I've rarely experienced that. Infact, I tend to find that 99% of the field are so incapable of balancing their ranges that most 3 bets are almost exclusively only with their big hands so 4betting tends only to be the top 10% of hands.