Looking for user experience with the K11+ bags

I would like to buy the K11+ for a 600sqft condo with a small dog. I would rather not spend ~CAD$30 a year on bags.

Is that 90 day bag emptying based on larger areas? Would dog hair reduce this? Could I manually vacuum out the bags to extend their life or is it just them getting clogged with dust? I wonder how long until AliExpress has third party bags, so far I only see k10.