This issue is similar to WT-5890 to go into the 4.2 branch that will set the minimum version that someone who has upgraded to MDB 4.4 can downgrade to.
Verify WiredTiger's durable history content release configuration settings
Prepare support with durable history: backport data format changes to 4.2
Bump log/WT version to facilitate upgrade/downgrade floor for MongoDB
Implement a downgrade floor between 4.4 and 4.2