I would like to share my experiences with HEN.
I have over 100 ISO which I made from my origininal discs using Multiman. All of these games boot fine, no problems, no black screen no need to do anything.
Another batch of games are games which I have created from scene releases, I also, have converted them to ISO using PS3 ISO rebuilder, checked IRD to make 1:1: rips. All of those games boot fine, zero problems.
One more batch of games are games which I have created from scene releases, but could not check IRD and verify the ISO, so they were made with PS3 ISO rebuilder GenPS3iso tool. 99% of these games work, only one game does not work for me and it is FIFA 19 neither US nor EU releases, I do not know if it a bad release or it is incompatible with HEN, because on CFW it boots without any problems, have not checked PSN versions.
If you want better compatibility with HEN I would recommend to use ISO format, build your ripped JB games to ISO using ISO rebuilder and check IRD to know if it matches 1:1. A lot of releases have split files to .66600, before you build ISO you have to merge them (even if you do not check the IRD, still join them), I also put update file in PS3_UPDATE folder before creating ISO even if I cannot check the IRD.
Split ISO work as well as merged to me does not matter if internal or external drive.
Guys do not forget that this thread is not about discussion of scene releases, but about HEN compatibility. Talk about 1:1 rips which you created yourself or made with PS3 ISO Rebuilder with IRD check.