That is very disappointing as it would seem Bosch have only done half the job. Without the HR being saved as part of the ride stats, only having it on the display little more than a gimmick, I already have that with my Garmin 530 synched to my watch & that does add the hr to the ride recording.Some more info from EBIKE24 Blog that might be useful. I seem to have found the answer to my question regarding not being able to see post ride heart rate data.
EBIKE24 say " As welcome as this innovation is, the fact that the values are only displayed while you are riding is disappointing. Neither the displays nor the app save them in the tour recording. Unfortunately, you can’t see afterwards how much physical exertion you were under at what point during the ride."
Thats a shame