Hi @misjah welcome. This is general advice, I do not own the device.
I see that there are “old” Android 11 (R) ROMs (actually out of date) and “new” Android 12 (S) ROMs available. Check here for /e/ ROM naming convention.
For the up to date Android 12 (S) ROM perhaps refer to https://doc.e.foundation/devices/natrium/upgrade, that is the Upgrade page, where we see
Warning: Please note this upgrade build could not be tested as there were no device specific testers available. Some devices may need a revert to stock ROM prior to upgrade. To flash the stock ROM you would need to use a tool provided by your vendor.
You may also need to download a recovery image built specifically for your device.
- (my emphasis)
I do not know the manufacturer firmware revision history for this 2016 device.
You would be best to establish the final firmware revision for the device. Use that unless (unlikely) it is in advance of the /e/ Android version you intend to install.
It is possible that (even following the above) you install a firmware with Android Security Patch Level (SPL) in advance of the current /e/ ROM.
With factory firmware installed check Android SPL on the device; for /e/ ROM check current Release notes, today I see
Security fixes
This /e/OS v1.13 includes the Android security patches available until June.
For a build “declared untested” often useful to cross reference to the Lineage wiki (/e/OS is a fork of LineageOS).
- https://wiki.lineageos.org/devices/natrium/update
- https://wiki.lineageos.org/devices/natrium/upgrade
where I see more specific information which I think may be useful.