It'll likely be a big hill to climb to get dedicated trail directions at Illiniwek. Depends mostly on working with the Ranger and how he/they want to run the park.
In the meantime we all could do our part in advocating the "Rules of the Trail", most notably --
#3 Control Your Bicycle. Ride within your limits and the limit of the trail. Know the trail systems in the QCA are busy and expect riders, hikers, and other users around corners.
#4 Yield to Others. As cyclists, we are at the bottom of the totem pole when it comes to yielding to other users. You always, *ALWAYS* yield to a hiker, equestrian, dog walker, etc. I've stopped and talked to numerous hikers at Sunderbruch and they're surprised I'm stopping and dismounting to allow them to pass--their response is a resounding Thank You--I let them know bikes always yield to hikers, to which I typically get the response of "sure wish they all would do that." Further, and just as important, when going downhill you always yield to another cyclist travelling uphill.
Of course, not many users are aware of these "rules" so as the local MTB advocacy club we all need to do our part in practicing and communicating with other trail users.