Is your feature request related to a problem? Please describe

Currently, the project uses some hardcoded Duration values in animations or transitions for many different controls.

This limits customization and forces users to modify source code for changes.

Describe the solution you'd like

extend the needed dictionaries in app.xaml/ResourceDictionary.MergedDictionaries

now:
<ui:ThemesDictionary />
<ui:ControlsDictionary />

suggestion:
<ui:ThemesDictionary />
ui:VariablesDictionary/
<ui:ControlsDictionary />

for all relevant controls: use variable instead of hard coded value.

Then the controls can be more customized by custom sets in VariablesDictionary

Describe alternatives you've considered

No response

Additional context

No response