What's wrong with a bounce rate of 26%? From Wikipedia:
Bounce rates can be used to help determine the effectiveness or performance of an entry page. An entry page with a low bounce rate means that the page effectively causes visitors to view more pages and continue on deeper into the web site.
According to Inc.com article: "As a rule of thumb, a 50% bounce rate is average. If you surpass 60 percent, you should be concerned. If you're in excess of 80 percent, you've got a major problem.
A low bounce rate is a good thing!
I was also concerned about the lower bounce rate in the beginning, but after doing some research about how the code in my plugin works, I understood that this is actually the real bounce rate. And the method used by the plugin is accepted by Google (it's their own code:https://developers.google.com/analytics/devguides/collection/gajs/methods/gaJSApiEventTracking) so you don't need to worry.
I have a website where the bounce rate is 1.11%. Without the plugin. No need for the plugin although it will probably go down a bit more...
But to answer your question. Every 10 seconds, the plugin lets Google know that people are still on your website. What you could try is to increase this number to let's say 30 seconds and see what happens. And if there is not much change, try to make it one minute.
In the code it's this part:
_gaq.push(['_trackEvent', 'Time', 'Log', tos]);
10000 is 10 seconds, 30000 is 30 seconds, etc.
Maybe in a next update, I will add an option page where the number of seconds can be filled in, with a default of 10 seconds.
Thanks for the idea!