okaaay 
i will sort the remote building out a tad bit later once i figure out THIS config first…
i actually have completely forgot about other useful flakes in my collection (commented out in similar fashion as the other 7000 lines… EDIT: 13000 lines…), where one of them SEEMS TO HAVE a cachix for jovian-nixos as well… apologies for having such a terrible memory.
and it has this jovian.devices.steamdeck.enable option, which also contains the kernel, linux-6.11.11-valve19, as of now. and with that, i no longer have to compile it for 2 hours every time!
so… that’s pogress right there!
EDIT: OOOOH SNAAAP! look what i found:
https://app.cachix.org/cache/jovian
AND
https://app.cachix.org/cache/jovian-nixos
(EDIT: nevermind. this still doesnt add the kernel to the binary cache)
i just put jovian after app.cachix.org/cache/ in and found cachix for jovian this way, which is… undocumented, i think? well, that’s another way to get cache!
P.S. i keep having this annoying issue with power management, where every time the battery reaches around 30%, it disconnects all USB (i.e. my dock station). and i didnt have this problem before jovian-nixos, but i have also started using services.tlp. since then with everything set to "performance"… and nor "usbcore.autosuspend=-1", neither services.tlp.settings.USB_AUTOSUSPEND helps… but that’s not the end of the world, is it? keeping the steam deck always plugged in will sort it out, surely 
edit: forgot to give an update whether this is true… NO. it does NOT have binary cache for the steam deck kernel even with all of those cachix caches provided, so, compiling for 3 hours every time there is an update? - unfortunately, YES. 
BUT!!! cachix from chaotic flake DOES work. so use that
also… the correct way to install a kernel (in my case) wouldve been boot.kernelPackages = inputs.jovian-nixos.packages.${pkgs.system}.linux; (according to this), but it doesnt work… because the flake.nix of jovian-nixos is pretty bad (sorry). 
other than that, its pretty good. so, im not using any of those steamos option features, i find them absolutely useless, cos im not using steam anyway, cos im using a steam DECK with a DOCK station to do DESKTOP things, not necessarily what its supposed to be all about (about valve or steam - no, its just a weird looking LAPTOP with built in joysticks to me, that i have disabled in its BIOS, as well as the touchscreen - just a waste of battery), but as a “tool to do everything else apart from gaming because i dont have anything else really”… though, okay, i do game a little bit, but only when im not hyperfocused on fixing my schisophrenic config. dont mind me haha
EDIT2: now that im thinking about… btw sorry, too many edits of an edit, DONT CARE. listen: the way it downloads the kernel is pretty weird. so it downloads a regular ass linux kernel package, without any binary cache, then it compiles for 2-3 hours and applies 4 specific patches… the last part? i can do myself. there is an option for it - boot.kernelPatches. and im thinking i can just simply yoink the patches from jovian-nixos and apply them post-factum on a kernel of my own choosing, e.g. zen… is that a good idea? there is only one way to find out!!!1