I’m not sure it is the right place, feel free to move / copy / paste somewhere else, sharing my trouble/workaround to install on S5 LTE :
The heimdall print-pit failed either with the version served by /e/, 1.4.2 or the one from Debian (1.4.1), with the following error:
ERROR: Failed to receive handshake response. Result: -7
ERROR: Protocol initialisation failed!
After investigating, I found this bug fix https://github.com/Benjamin-Dobell/Heimdall/pull/225/commits/6b826dc1707840240438646b62011edb8fb87a53 . I applied it on current master of https://gitlab.com/BenjaminDobell/Heimdall/-/tree/master/ , compiled, and it worked (some warning at the end, but not critical).
Then after transfering the .img with adb, as i wanted to reboot, i got a warning that no OS was present/detected. I rebootet anyways and everything worked actually fine 