I have never used SendtoReader. Instapaper has a link that you can add to your web browser that saves the article for "Read Later" to be compiled into an ebook. I usually send the compilation to my Kindle email (so it shows up wirelessly). You can also go to your account page on Instapaper and download the file in EPUB format for the T1. You can download through the T1 web browser or save to disk. There are a few quirks though. See the attached post.
https://www.mobileread.com/forums/sho...d.php?t=161834