What this means, more or less, is that it's possible to to delete all of the precombined meshes you have generated for a cell, except for the ones containing new information. Any other mod that edits that cell, but not the exact area which your changes have been made, will be compatible, so long as it also only includes only the precombined meshes containing its mod information.
Unfortunately preocclusion system works not on per cell base like precombined meshes, but on 3x3 cells blocks, and mods that don't change the same cells still can conflict if they include those regenerated precombined and preoccluded files. They can make changes in worldspace which are two cells apart from each other, won't show any conflicts in CK and FO4Edit, but if they happen to be in the same 3x3 preoccluded block and change the same uvd file, they will conflict and cause visual issues. This is the biggest flaw of that system. In previous games mods had to change the same cells in exterior to conflict (or at least neighboring cells if landscape, pathgrids or navmeshes were involved) and such conflicts were easy to detect and create compatibility patches. It is no longer true in FO4.
The second problem is that precombination info is stored in the cell record itself, and if you regenerated precombination or just simply disabled it, this will work only if your mod is the last one in load order that changes that cell. So every mod author had to add "load my mod last" or "make sure nothing overrides it" in the description. Imagine a poor user with lets say 30 mods installed that change interior or exterior cells with updated precombination, each telling him to be loaded last. Add here conflicts from lighting mods which also have to change information stored in cell records, and they also will tell to be loaded last to work properly. Yes you can still create patches and forward conflicting cell information in FO4Edit, but if author of one of the patched mods will regen precombination, even if his new changes don't cause additional conflicts, all patches will have to be remade anyway due to changed precombination info.
The system is flawed. It worked for Bethesda and their game plus DLCs aka static, fixed and predictable load order, but it doesn't work for modding. At all.