The biggest practical advantage is not “5.3K looks dramatically sharper on a 1080p screen.” It is the room you get in post.

You can crop, straighten a horizon, add digital stabilization, or create a vertical/social version while still retaining enough resolution for the target. If your framing is already perfect and you never crop, the benefit is smaller.

That is why I like higher resolution on helmet footage. My camera angle is never as perfect as I think it is before the ride. A modest crop can turn a clip from “too much sky” into something usable.

For a fixed tripod shot where I know the composition, I am much more willing to use 4K and save card space.

Also consider the cost on the editing side. Resolution is only one variable; codec, bit depth, frame rate and hardware decoding matter too. 5.3K HEVC at a high frame rate can be far harder to edit than 4K even when the visual difference in the final video is modest.

If storage is cheap but your computer is the bottleneck, proxies are often a better compromise than permanently lowering capture quality.

That is how I would frame it. Capture high when it buys you post-production flexibility, then use proxies so the timeline does not pay the full decoding cost. VSDC, Resolve and Premiere can all support that general proxy strategy in different ways.

For a 1080p final, 5.3K gives a lot of reframing headroom. For a 4K final, the margin is smaller, so I would be more selective: scenes likely to need crop/reframe at 5.3K, simple long takes at 4K.

I like that approach better than one global “always max resolution” rule. I am going to make two presets: 5.3K for helmet/handheld action where I expect reframing, and 4K for controlled shots and long recordings.