After further investigation I think the problem is present in all versions of the firmware.
Regardless which drive is used to read the disc, for all empty DVD+R media ID is always reported, but for some written DVD+R media ID is reported and for some it is not. For example for discs written with Plextor PX-891SA media ID is reported, but for discs written with Samsung SH-224BB it is not.
With old versions of DiscSpeed when running two simultaneous tests, opening the tray of one drive disrupts the test (graph) of the other drive.
I have an iHAS124 F and jitter works with 188.8.131.52.