This looks more consistent with other templates to me.
-InsetLayout "Flex:Abstract"
- LabelString "Abstract"
+Style Abstract
+ Margin First_Dynamic
- LaTexName abstract
- LyXType Custom
+ InTitle 0
+ LatexName abstract
+ LeftMargin MMM
+ LabelIndent MMM
+ RightMargin MMM
+ ParIndent MM
+ TopSep 0.7
+ BottomSep 0.7
+ Align Block
+ LabelType Static
+ LabelString "Abstract."
+ LabelSep M
+ Font
+ Size Small
+ EndFont
by Author A and Author B
\end_layout
by Author A and Author B
\end_layout
-\begin_layout Standard
-\begin_inset Flex Abstract
-status open
-
-\begin_layout Plain Layout
An abstract of less than 150 words.
\end_layout
An abstract of less than 150 words.
\end_layout
-\end_inset
-
-
-\end_layout
-
\begin_layout Section
Section title in sentence case
\end_layout
\begin_layout Section
Section title in sentence case
\end_layout