Access / Attic Revision

Hello.

In our case, the attic/crawl space should not be accessible, so there will be no retractable ladder (in order not to worsen the insulation here and not to let moisture in).
The majority of the roof insulation is also placed at the level of the middle collar beams.

What are some proven solutions to still have an option for maintenance here, meaning an access that might be needed only every 10 years (or never)?
A gable window that can be opened from the outside? Other ideas?

Thanks in advance for your suggestions on how to solve something like this.

Every cavity is also a potential incubator. Even filtered air carries particles. I consider the idea to be illusory. Where does the chimney sweep get out?

I think so too. Karsten