Yo Carl. If you're willing to edit code, search for the string "truncate_len" in packages/lars-blogger/tcl/rss-procs.tcl. You want to change the line that looks like this
set truncate_len 100
to
set truncate_len 500
We probably want to turn this into a package parameter.
I went and edited the code and restarted the server. Worked fine, but in the process I discovered that images in an entry are not included in the generated feeds 😟.
Just noticed that Lars added it as a parameter that can now be set using the admin UI (now all I have to do is update my server).
As for the feed image, that was MUCH easier than expected... it turned out it was already a parameter in the admin interface: http://openacs.based/blog/admin/