Could you make an exchange of pollution between different surfaces of the plants in both directions?
So it would make sense to use them with air filtration mods. You can even use a certain multiplier - two times more is transferred to outside than inside.

EDIT:
On the surface, can you set the level of dispersion of pollution? Why not remove it at all (0), and then the idea is only to suck air in if the pollution inside is much lower than outside. Here, it might even be worth taking out a certain configuration parameter-multiplier to calculate this difference.

I'm not motivated to add this. Vanilla has no options for air filtering and the mechanic is only used in a handful of overhaul mods.
Additionally, if factories could store pollution, what is stopping players from building a bloc of empty factories to prevent pollution spread.

Perhaps if pollution is reworked in the factorio expansion I can take another look at it.

do you have GitHub/GitLab repo for this mod, so we can provide some optional extensions via an option in the settings (through Pull requests)?

There is no repo for this mod, but feel free to upload a forked version to the mod portal.

I would also really appreciate something like this. I'm using Factorissimo along with AngelBob mods, and several of the bioprocessing buildings have negative pollution production. It would be nice to take full advantage of those buildings' pollution absorption properties without having to leave them on the overworld.