@Sobieck
Checkout: #GearLever to easily manage/update/integrate #AppImage apps into your system:

https://flathub.org/apps/it.mijorus.gearlever

ProtonUp-Qt is great to easily use GE-Proton Versions (Think experimental, with extra steps/goodness):

https://flathub.org/apps/net.davidotek.pupgui2

https://github.com/GloriousEggroll/proton-ge-custom#overview

https://github.com/GloriousEggroll/proton-ge-custom/releases

For Valheim, I use the R2Modman AppImage to use Thunderstore Mods:

https://github.com/ebkr/r2modmanPlus/releases/download/v3.1.55/r2modman-3.1.55.AppImage

https://thunderstore.io/c/valheim/

>>>>> For How-2-setup BepInEx:
https://thunderstore.io/c/valheim/p/denikson/BepInExPack_Valheim/

0194af93-a622-406f-91d8-e7ef06f29b4b
is my "code" for the plugins I use.

https://thunderstore.io/c/valheim/p/Azumatt/AzuExtendedPlayerInventory/

is what I use for extended inventory myself.

While Valheim will play native, I couldn't get mods to work until I set it to play through proton.

I also copy/paste my r2modman plugin folder to my Valheim plugin folder :(

r2MODMAN_DATA_FOLDER_HERE/r2ModmanPlugins/Valheim/profiles/Default/BepInEx/plugins/

>>>>>>

/home/USER_NAME_HERE.steam/steam/steamapps/common/Valheim/BepInEx/plugins/

Until someone can help me figure out otherwise t.t

Benefit of doing it this way.....I don't need to edit my launch properties at all anywhere...I just use:
mangohud %command% -console

https://github.com/flightlessmango/MangoHud

To enable MangoHud stats and enable console for devcommands & debugmode