AC made a "shortcut" with just storing everything in "Imported Items" rather than actually in the record. This does leave you with a large number of PDF's and it's just not practical to bring all those into another EMR. Praxis uses much smaller HL7 files that get imported directly through interfaces, like from you lab company, imaging company, hospital, and so on. They work actively with vendors to provide interfaces that bring data items directly into the chart. These much small files don't hog gigabytes of space, like PDF's do. AC PDF's have no name convention that links them with a patient, they have nonsense file names, so it's no possible to have a program that brings them all into a certain patient's chart. That would have to be done manually.
So, the government has mandated years ago that EHR's output files that can be directly imported into another EHR, so that patient's can easily transfer records. AC has always had the verbage that they are compliant with these government mandates, but AC has not set themselves up to be compatible with others, and no one really wants to, despite being mandated by the government to have exported EMR files that can be imported into other EMR's. When you export the files from AC, they actually are not compatible when tested with the government test website. The files are unreadable by other EHR's.