The fact is that the Virgo team has now significant less resources than it used to be in the past and is not able to evolve all the flavors of Virgo anymore, therefore we need to concentrate on the variants that are most used.
Current VJS ships with a rather old Jetty, version 8.1 which already reached end-of-life. A new Virgo release would need to ship with a 9.x version and none of the active Virgo committers is familiar with Jetty. As you can imagine, a Web Container is a complex component which requires careful integration and testing.
While your offer to test the product is much appreciated, the remaining effort for upgrading and integrating Jetty is still too high for us at the moment. Of course Virgo is an open source project and we welcome contributions.
Besides, based on your answer I believe it should be possible for you to switch
to Virgo Server for Apache Tomcat with limited effort. Should you
encounter any issue you can post to the forum and we will try to help
you as much as possible.
GianMaria.