I have two approaches ... if the model's only purpose is for visual impact I sometimes model at an exaggerated size IF I find I can get the scene to look better, BUT if the model's purpose is to show how the thing will look when actually built (such as scenic in a TV studio) OR if the model will be sent to others who have to work from it in the real world (such as a fabricator or lighting designer) then I work at 1:1 actual scale. Hope this perspective helps.

WARNING: Redshift 2025/2026 with MacOS 2026 Tahoe on Intel will crash Cinema 4D on launch.
At present, Maxon reports that Cinema 4D will crash on Intel CPUs under MacOS 2026 Tahoe. Maxon: "It is a known issue as of yesterday that our development team is still researching." Further testing suggests that Redshift itself is the cause. Removing Redshift allows Cinema 4D to launch.