First of all, I installed e-Recovery T V1.17. The Tab S3 does not boot into e-Recovery, but back into Samsung download mode.
Now I installed TWRP Recovery 3.6.0_9, which worked right away. After formatting, I installed @ronnz98’s e-1.17-t-20231202-UNOFFICIAL-gts3llte.zip via TWRP from the USB stick, which went without errors, but - the subsequent reboot into the system failed. The system reboots into Samsung download mode.
Update N° 1
I installed TWRP 3.6.0_9 again, than lineage-19.1-20231115-UNOFFICIAL-gts3llte.zip by @ Awesometic which went off without a hitch. gts3llte LOS system booted correctly.
Update N° 2
I installed TWRP 3.7.0_9 again, than lineage-20.0-20231116-UNOFFICIAL-gts3llte.zip by @ Awesometic which went off without a hitch. gts3llte LOS system booted correctly, but @Awesometic’s ROM has a serious flaw = 4G LTE does not work!
From the running system lineage-20.0-20231116-UNOFFICIAL-gts3llte.zip by @Awesometic I installed via TWRP 3.7.0_9 as ‘Clean install’ @ronnz98’s ROM e-1.18-t-20231216-UNOFFICIAL-gts3llte.zip
The reboot ends in Samsung download mode “Downlading … Do not turn off target”
As a second attempt, I installed the e-Recovery T-v.1.18 with the help of TWRP 3.7.0_9. The reboot also ends up in Samsung download mode. TWRP is now no longer on the system; neither is e-Recovery. A manual start in a recovery now lands immediately in Samsung download mode.
Additional note:
I installed TWRP 3.7.0_9 and lineage-18.1-20231115-UNOFFICIAL-gts3llte by @Awesometic without any complications. Everything works: 4G LTE, USB-C OTG … This is a good example of how higher OS versions don’t always provide a better user experience.
The /e/OS-R version for the gts3llte works also fine (I own the device myself).
Though I like Android R still most of all Android versions, end of live of R will be reached in about a year. Android T has support for 3 more years at least…
does not work for me e-1.19.1-t-20240114-UNOFFICIAL-gts3lwifi.zip