I don't mean to be mean here, but I think it's best left alone. My reasoning why:
With current cleaning/smoothing algorithms, it wouldn't be hard to take resolution limited at 6000px w/h and produce relatively good 8k content.
That being said, with it limited to 5000px it's more beneficial too downscale to 4K for super crisp results, or upscale a tad to 5k resolutions.
This keeps Creative, imo; in scope with a lot of resolution limitations in other software. With 8K becoming more standard, this gives users a incentive for TG4 Professional.