🚀 go-pugleaf

> We would like to insert the text inset between two topic titles.
> When we do this, an empty paragraph tag appears under the text inset.

Well, not really. A text inset has to be anchored to a paragraph.
This is the paragraph in which the cursor is placed when you
import the inset. If you anchor it to an empty paragraph, then
that paragraph will still be there, empty except for the inset anchor.
(There is no "anchor" symbol associated with an inset)

> When we delete the paragraph tag, it seems that the last topic
> title becomes a part of the text inset.

No, it doesn't. The topic title is placed in the same paragraph as
the inset anchor, that's all.

> When you update the FM book, go to the TOC and click on the link
> of this last topic title, the whole title and text inset is selected, 
> not only the title as it used to be.

And why is this a concern? The inset should work as expected.
The reason is that if you follow a TOC link, the whole paragraph
becomes selected, including the inset anchor and the inset.
If this bothers you for some reason, you need to anchor the inset
in a VERY small paragraph between the two topic titles, say 2-pt
font size with zero space above/below.

-- 
/Thomas Michanek