There is saned@.service, but @ looks useless because there are no template specifiers inside the unit file, and probably none are needed. It should probably be renamed to saned.service.
Also, there is an udev rule which adds saned in ACL for scanners, but maybe it is better to add saned user to group "scanner"?
thank you for reporting the issue!
The saned@ naming is chosen according saned manpage, so it will need to be changed too - but I don't see a reason why it shouldn't be done.
However, I don't see a 'scanner' group in my F33 machine (in /etc/group) or in any udev rule. I would expect the group is being set somewhere in other udev rules, since it needs to be applied on usb device to make saned work (if saned user will be in scanner group). Or do I get it badly? Saned user works, so I don't see a reason to change something which works.
I'll report the saned naming upstream.
actually saned@ is a correct name too according 'man systemd.socket':
Depending on the setting of the Accept= option described below, this .service unit must either be named like the .socket unit, but with the suffix replaced, unless overridden with Service=; or it must be a template unit named the same way. Example: a socket file foo.socket needs a matching service foo.service if Accept=no is set. If Accept=yes is set, a service template foo@.service must exist from which services are instantiated for each incoming connection.
Based on that, I'm closing this as NOTABUG.