Ah, one of my favorite topics!
1) The mandated posting of test results and doctor's notes IS EXTREMELY VALUABLE TO PATIENTS. Everyone should read their records or get someone to help them. The Doctor's notes remind me and/or give me more background on what he/she is really thinking. The test results and especially CT/PET/MRI scans describe findings. Because I could read the CT scan, I immediately requested my records be sent to Mayo. The local specialist was not knowledgeable and wanted to do certain tests that would have been risky for me. I also add that one should be sure your specialist has knowledge of your specific problem. There are subspecialties under the Specialist umbrella, so they are not all equal!
2) The flow of medical records between institutions still needs to be improved upon. Big places use EPIC, but smaller medical groups do the minimum required by law, and do not have the IT personnel to forward records. One issue I see regards tests with numbers like blood tests. If done in one big place they provide the ability to chart previous values. But when this test is sent to another institution, it goes as a "document" and not "data" so it cannot be analyzed easily (somebody would have to enter the data) .
IDEALLY all medical records should go to one big global database, and institutions treating the patient would pull the record down - that would provide one database design so information can be analyzed.
THE FUTURE - once we get everybody's clinical profile into a well-designed database, the potential for medicine is incredible. For example, one can track easily how a certain medication works for people with different blood types, of different ages, with different problems or whatever is relevant. Example is with Covid. States are tracking, but not all in the same way so we lose information. Ideally, they should tell you when you got vaccinated, time that passed from vaccination when you got Covid, profile of who is sicker etc. That would help in deciding best time for boosters