Official comment
The Play Store variant is the 'a' variant. The 'b' and 'e' variants are for APK download and have the same bundle IDs and therefore are not able to be installed on the same device at the same time. The 'b' and 'e' are kept separate from the 'a' variant for crash logging differences.
The 'b' variant runs the DJI SDK 4 for older devices and the 'e' variant runs the DJI SDK version 5 which is what they have the new devices using. They cannot be combined because of issues within the DJI SDK.
For some reason when DJI released version 5 of the SDK they made it separate from version 4. So everything before the Mavic 3 Enterprise was on SDK 4 and everything after is on SDK 5.
There is zero chance of combining them unless DJI goes back and updates the old version and new versions to be compatible. DJI has said they will do this at some times and said they will not at other times. We are guessing it isn't going to happen at this point.