hholzgra
Add an additional final step: Save permalink
Perhaps, to save disk space on the server, add an additional final step: Save permalink.
I.e., only create a permalink like https://maposmatic.osm-baustelle.de/results/2021/12/27/197936_2021-12-27_16-58_dan-s-map.jpg (or even additional short version too) if the user is happy with the results, and wishes to save a permalink too them. Else don't put https://maposmatic.osm-baustelle.de/results/2021/12/27/197936_2021-12-27_16-58_dan-s-map.jpg in the URL bar, and don't keep any info from this session on the server.
I had thought about adding a user management system at some point, where registered users can have features like permanent storage, higher render priority, maps that are not publicly visible, etc. ... but so far never followed through on this.
Given that rendered files are usually available for at least two months, and can easily be re-generated that was never really an issue yet, but I understand that it would be if you'd like to generate printable maps for public use that should be accessible for a longer time frame.
Yes currently apparently some links are just generated sequentially, allowing some users to guess other users' maps, and thus discover buried treasure locations...
But anyway however long a link is supposed to last always needs to be mentioned on the same page with the link.