Priority has no effect on updates. Packages stick to “vendor”, whatever the priority of the source repo might be.
Priority affects new installs, so whenever you choose to install anything that is available in Packman you get it from Packman, which might not be what you want, generally speaking.
Here:
Yes, if want to switch, then use the --allow-vendor-change (Is that an option in Myrlyn?) I’ve never had an issue with leaving everything at the default 99.
Something that, I only really used, ever, when upgrading from Leap to Tumbleweed – the zypp.conf man page has some warnings { zypp.conf section [main] } –
solver.allowVendorChange (false)
[Expert Only!] Per default the solver will not replace packages of different vendors, unless you explicitly
ask to do so. Setting this option to true will disable this vendor check. Packages will then be considered
based on repository priority and version only. This may easily break dependent packages because different
vendors may use different default settings or version schemata.
solver.dupAllowDowngrade (true)
solver.dupAllowNameChange (true)
solver.dupAllowArchChange (true)
solver.dupAllowVendorChange (false)
[Expert Only!] The resolvers distribution upgrade(dup) job uses differernt defaults regarding package
version downgrades, renames, architecture changes and vendor protection than ordinary install and update
jobs. It’s not recommended to amend these defaults without need. In case of doubt zypper(8) provides command
line options to do this for a specific job only.