Are you aware of this page, it is specific to herolte – is this your device? There was this support topic Upgrade the Samsung s7/s7+ to /e/OS R with SD card set as internal storage.
v1.17.1-q · e / os / 🚀 Releases · GitLab
I gave this answer Upgrade Samsung S7 to e/os 2.4.1 help needed, please - #2 by aibd maybe there are some useful links from this thread.
However due to the outage of /e/ servers the 1.17.1 herolte ROM cannot be downloaded at present.