are you studying part time or full time? If full time you have plenty of time until April given your current practice scores. If part time, be realistic about the number of practice problems/exams you can complete vs the amount of time you can give each day/week. In the end though, it’s not about finishing all the practice problems as it is about getting your AAMC full length scores to a consistent and comfortable number in your goal range. You seem to be making great progress but it’s hard to say because most of your practice exams are third party. If you’re not there yet, it’s okay to give yourself time. Also, have you already registered and do you know for sure that you could get a slot in either date?
Whether someone’s actual score goes up vs their practice is pretty individual. If you have test anxiety you might have the opposite problem. Otherwise it is totally possible to do better, but never a guarantee because the content that shows up on your exam/how difficult it is for you personally is kinda of luck of the draw. Personally I scored +3 more on the actual than my highest practice exam and did well. I never felt completely ready with all the content but my practice exams scores were very consistent.
In the end, either timeline is fine. Either way, if you don’t score well, you have time to retake and still apply this cycle. If you choose to take the exam in May, I recommend you start writing your primary before then in parallel, maybe as a “break” in between MCAT studying.
I remember being in a similar position last year, feel free to reach out if you have more questions. Good luck!