Yeah that should definitely be enough, long as it's done consistently. Typically I do 2 days a week for abs, 2 exercises for 5 sets each, usually rope cable crunches and ab wheel. So 3x a week would certainly be enough, and 2 might even work as well. You really have a pretty complete physique and will keep improving no doubt, abs seem to lack some of the definition you have everywhere else. It's easy to spot the guys on stage who don't prioritize abs, and having a great mid section makes every front post look that much better. Keep up the great work man, and keep us posted once you get ready to compete!