when I create a new style and the cursor remains on the modified text from which I created it, this specific new style is never selected in the styles panel but always the previous style with the "+" sign

This is by design. Creating a style (in general) from a selection does not automatically apply that style.

The only important thing missing for a more complex and complete layout in vector app would be a hierarchy of paragraph styles. I haven't yet tested the interaction between paragraph styles and character styles.

in VS, even when editing the style, I can't see a way of creating a sub-style that depends on another:

Can I establish a dependency from one style to another?

Apply style "Title_1", make some changes and then create new style "Title_2" from selected text.
"Title_2" should be dependent on "Title_1" for the parts that are not changed

For example, I've defined a "Title_1" style that applies to my first page title and then I want to use the characteristics of this style except for one parameter. For the moment I can't see any other option than to create a new style "Title_2" which is totally independent of Title_1.

This means that if I want to make a common change to all my titles (e.g., I decide to change the font) I'll have to make this change to all my title styles. If I only have two of them, that's fine, but if I create multiple sub-styles from a single one, it would be nice to apply a change to all of them by changing the "master" title.

I did not test "copy a style" and therefore do not known whether it creates a link between styles.

when I create a new style and the cursor remains on the modified text from which I created it, this specific new style is never selected in the styles panel but always the previous style with the "+" sign

I will try to fix this.

Just one small detail I've noticed (reproducible): when I create a new style and the cursor remains on the modified text from which I created it, this specific new style is never selected in the styles panel but always the previous style with the "+" sign. It's a minor detail, since all you have to do is reselect the style, but still.

To test synchronisation, I change some of the text parameters (font, size) and try to update the style I've already created... it doesn't work as expected.

Found one issue, the fix will be in the next build.

It is still not possible to synchronise a text modification with a paragraph style that has already been set up

To change the style from the selected text or to apply the style onto the selected text?

"Ressources" folder sent

I tried to repeat this problem but VS crashed (crash report sent).

Got the crash report. Was the Guidelines panel open? Seems to be caused by that.

Please send me the workspace and settings files (Help -> Reveal Workspace Folder).

First, I was able to define a paragraph style and apply it to different parts of the text. It was easy to switch between the two styles.

If I select a piece of text in a paragraph (with a paragraph style, e.g. title) and change the characteristics of the text (font, size, etc.), the synchronisation doesn't always work and I always ended up with "unstyled" text, and Ctrl+R does nothing.

I didn't record this time, but it's like at the end of the video I sent you earlier.

Paragraphe style panel.

I made a recording of the paragraph style syncing: https://recordit.co/0kiu9aB4s9

Maybe I do something different here, attached the file also: 0_1701886168646_paragraphstyle2.vstyler

In this file I have the default paragraph style and a new (not yet edited) "title1" style. In the text I changed some character and paragraph attributes, but still links to the default style at first.

The syncing is done with he highlighted button (below).
One problem: if the panel is set to apply the style in a single click, then syncing will not work, since by selecting the style (to sync) will apply the style, so there is nothing to sync.

synchronisation is not always working as it should

Does this refer to the character panel update, or to the paragraph style creation from the "Paragraph Style" panel?

Edit: no, synchronisation is not always working as it should. Sorry, I stop testing this up to the next updates.

This can be replicated.

I could not replicate these two, or I did not understood them:

it can be applied to another paragraph without taking all the defined criteria into account
it can be applied to another paragraph but reverting to the default style is not correct, as the text may retain the font size of the new style