I just finished flashing. Once the recovery image was flashed, everything went very smoothly.
But before that I ran into a few issues that might be clarified further in the documentation.
- Make sure that you stay connected to wifi at all times. This might reduce the chance that a Samsung device sinks into ‘Prenormal KG/RMM state’, and this could potentially halt the installation process for 7 days. (Also, it took me some time before I realised that I actually was in prenormal state myself, so it is good to emphasise
checking whether the OEM Unlock toggle is missing.) - I didn’t get Heimdall working after many, many attempts. I agree with @Luke to suggest the alternative ODIN install for Windows users. This would make the process much smoother.
- Me, personally, I didn’t want to use ODIN this time, as I thought I had to first manually flash TRWP as well; (this is suggested in another forum thread ). But because I couldn’t find the right version for the S6 Lite, I didn’t want to go there initially, until I got really fed up with heimdall. So a side note that manually flashing TWRP is not needed here, would have made the installation easier.
So far my suggestions, hope they are useful.
The rest was really super smooth!
(And now i am going to play with my first-ever, privacy friendly tablet. 
)