Example:

-----------------

\definetextbackground[placeholder][location=text,alternative=4]

\starttext

a.
\startcolor[red]%
b.
\stopcolor
c.
\starttextbackground[placeholder]%
d.
\stoptextbackground
e.
f.

\stoptext

-----------------

In the output, there is no space before "e" and there is a space before "c".

I'd expect spaces between neighbor sentences, whether textbackground is used or not, just like the usage of startcolor.

Thanks,

GOU Lingfeng