We can store PDF manuals for download at people.ubuntu.com and avoid any download costs for you. Ubuntu members can store files there, eg. an older Lubuntu 22.10 manual can be found at https://people.ubuntu.com/~nio-wiklund/LubuntuManual_version-22.10_2023-06-17.pdf uploaded by @sudodus
If you’re happy with storing the created manuals there, that is always an option; just ask (I’ve assumed you’re not a Ubuntu member, I don’t know your Launchpad ID to check sorry)
You can always modify this page and include pointers to them, OR create your page on this site that draws attention to the location of the PDF manuals. I can help with that (We’ll be sure to credit you with the creation of them on this site, even if we cannot at people.canonical.com sorry)
Thank you for creating the PDF manuals; that will be a HUGE RESOURCE that I’d expect would help end-users, some of which are offline most of the time. (I’ve been wanting to do this for awhile, but never got around to it)