got this working, too. Quote from the Release Notes:
The parameter for the Layout Template can now either contain an integer value (1..6) to select one of the predefined templates - OR - (new:) it can directly contain a path to a Layout Template file. The same placeholders work here as in the predefined Layout Template filenames, so you can e.g. use:
currently not, although i could extend the number of predefined templates to 9.
It would still be a limited number, though.
One thing i have thought about: Instead of specifying the number of the template ("tpl=1"), i could make it so that you can directly specify the path to the template in a preset or the invocation code like "tpl=%GPXDIR%/mytemplate.htm".
I like this better because it would give you an unlimited number of individual templates. What do you think?