Many thanks for the pics. They "always" say, there's more life to an air filter than we think.
This is what I think.
1) The air velocity drop which occurs in the lower portion of air cleaner housings allows heavier dirt to precipitate out.
ERGO the dirt which gets to the filter is finer. I believe this is plainly evident.
2) In the absence of repeated dirty exposure I think 30K is a great time to economically replace the filter. Mine look much like yours after that much time.
3) It's a good part to need periodically so you can add it to parts orders and reach 'Free Shipping" thresholds regularly.
4) I also think it's OK to avoid drilling a hole and risking creating a source of unfiltered air in your upper housing.