Put pre-comps into a "Pre-comps" folder automatically, just like solids
This could be a checkbox in the Pre-compose creation dialogue box. When enabled, precomps are automatically stored in a "Pre-comps" folder at the root level of the project. This would keep large projects so much tidier as we work. I always have to go clean up my dozens of pre-comps that are scattered all over in my primary folders.

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Michael Demetriou commented
Came here to request this exact feature.
It makes so much sense and Im sure an easy implementation for Adobe.
Should also be a feature in Premiere Pro for nests.You can now change the default 'Solids' folder name in the preferences under "New Project" settings.
Should be able to do the same for Pre Comps, with also the option to make the new Pre Comp folder as a sub folder of the parent to the current composition, OR a top level Pre Comp folder.