I’ve actually done a tad bit of video editing on my Deck through Kdenlive and in short, it works.

I think a general issue is that Kdenlive tends to crash in of itself a bit. The biggest limitor is probably the lack of GPU based hardware exporting available for the Decks APU in Kdenlive. As well as the 16GB of RAM.

What I specifically did was load in a video file about an hours length, cut it down and overlay some recorded audio to it, sync it up and export. It was sluggish, froze every now and then and crashed a couple of times. RAM and CPU usage was continuously at high. If I remember correctly, the video was in 4K recorded on an iPhone in HDR. At least the source video was, I can’t recall if I scaled it down to 1080p or not.

I do want to mention that I’m not running SteamOS on my Deck however. I believe at the time I was running Bazzite and now I’m running Nobara. I haven’t tried doing this on SteamOS but I would imagine the experience would be more or less the same.

Will it work? Yes, kinda. Will it be as good as an experience as running it on a full fledged desktop with more RAM, higher end CPU and a somewhat modern dedicated GPU? No, it won’t. It’ll work in a pinch or if you have time and patience.

Honestly it largely depends on your main PC specs, but like you are hearing from others. It probably isn’t a good idea.