In Krita's session user can setup diffrent "Tool Options >> Smoothing" for "Freehand Brush Tool" and diffrent "Smoothing" for "Multibrush Tool". I very like this behavior... But after restarted Krita these both Tools have the same (last used) "Smoothing" algorithm... This breaks consistency in Krita - nearly all other Brush Tool options are stored between sessions... Reproducible: Always
This is a shared setting across multiple brush tools in the code. If we want this to save separately, we will need to figure out how to separate the setting or add extra logic so it knows what brush tool it is on. This setting has been shared for a while, so we probably need to get the feedback of some different artists before we would do this. I could see different artists prefer different ways for this to work. Marking as a potential wish list item.
A nice solution will be implemented here: https://invent.kde.org/graphics/krita/-/merge_requests/559 since you will be able to have multiple tool options resets for all common workflows you use those tools for. Then sharing the options shouldn't be a big issue if you can easily swap between your chosen settings.