in XnView version 1.80.1, there is a box "Template Folder" in the "Web page Create" window (BTW, typo: "page" -> "Page"). To the right of it, there is a button "..." which opens a file dialoge, supposed to be a chooser for the template dir, right?
But the file dialogue seems to be a completely different one:

(1) It has the title "Output Directory" and
(2) no matter what I choose in there, it does not affect the list of templates listed in the "Template" list box
Luckily I can change this directory via the xnview.in file!

Regards,
Torsten