How to update to latest version but keep Kodi 18.x?

So, I’m still on Kodi 18.5 and OSMC November 2019 (2019.11-1) on my Vero 4K.

I want to update to at least whatever version of OSMC that has those HDR MaxCLL/metadata fixes from 2020 or 2021 (I think kernel 4.9 or something?), preferably even newer. My Vero 4K just sends 1000cd/m2 for everything.
At the same time, I can’t update to Kodi 19 because I have some addons that won’t work with Kodi’s forced Python3 requirement but those addons are dear to me.

Is there a way to update Kodi to 18.9 and update OSMC to something even newer separately? If not, how do I get the latest OSMC version installed that is not Kodi 19? Going through the “My OSMC” menu just wants to update me to the very latest version.

This is not possible.

So all versions of OSMC that actually send the correct HDR metadata are on Kodi 19.x?

We started sending the full HDR metadata with our 4.9 kernel; this was somewhat independent of Kodi version, with the exception of some formats like VP9.

Someone had a hack to send mastering data with the 3.14 kernel; but this wasn’t officially supported and won’t have the benefits that @grahamh has added to the OSMC video enhancement layer.

Sam

Decided to bite the bullet and just update. Turns out, it’s not possible to update??

There’s no way I’m starting from scratch. Is there any way I can do incremental updates? Surely images of previous version are still available somewhere for me to download and upgrade using SSH?

Images are available but they are installer images.

We don’t support updating from an image that’s three years old.
You can try it – but you should take a full backup beforehand.

Sam

Just to clarify: I downloaded an image from 2020 but I can’t use SSH/SCP or whatever to upgrade., right? Instead, I need to first back up using “My OSMC” to a flash drive, create an installer flash drive using the Installer app and the downloaded image, boot that flash drive, install, restore backup from the other flash drive… and then do all of this about 6 more times? There’s no way to just copy the .img to the Vero and run some command to upgrade?

We usually support an upgrade path from one Debian / Kodi release (about two years).

Images are not upgrade images – they are full installation images.
I’d try and take a backup, then upgrade and see if you can solve things from there if you really don’t want to start from the beginning.