Created attachment 157426 [details]
in sidebarparagraph.ui file the GtkSpinButton
are smaller than they should be which result into problems at sidebar width.
As sidebarparagraph is the widest sidebar AND the default sidebar (in writer) all other sidebar widgets follow the size of the default one, so if the sidebarparagraph.ui wasn't shrinked all other widths will be easier to fit.
Created attachment 157428 [details]
As you can see here the table sidebar didn't fit into the width cause the width size come from paragraph sidebar cause it's open by default. So if the width of paragraph was the largest or at least not shrinked, it will be easier to fit all widgets.
I take your point on the paragraph panel effectively setting the default width that other panels should be less than or equal to that to make it possible to align things between panels.
I don't think the spinbuttons are the true source of the problem, more the toolbox widths. Here's what I suggest...
a) The table "misc" toolbox is 2 GtkMenuToggleButtons and one GtkToggleButton wide that's about 5 standard toolbox buttons in width in gtk3
b) The paragraph top line of toolbars is about 9 toolbox buttons in width
If each of the columns in the two panels was 5 toolbox buttons in width they would align with eachother. So with https://gerrit.libreoffice.org/c/core/+/87462 I assign "indent" in sidebarparagraph.ui and "split_merge" in sidebartableedit.ui a width as if they had 5 toolbuttonsin them and that seems to give a good result.
Caolán McNamara committed a patch related to this issue.
It has been pushed to "master":
tdf#130197 give paragraph and table panels column widths of 5 toolbutton widths
It will be available in 6.5.0.
The patch should be included in the daily builds available at
https://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More
information about daily builds can be found at:
Affected users are encouraged to test the fix and report feedback.
Created attachment 157573 [details]
paragraph width border = 6 "missing"
I only have an windows daily build. There it look now really good, if the border would be respected it would be perfect.
the "style" and "character" panels are not converted to the new scheme yet, when they are it should be possible to also set them to use the same width based on the same no of toolitems and then hopefully they will align