Used to ride up there lots – XC stuff going way back before the bike park was a twinkle in guy with a shovels eye.
There were a couple of badly way-marked routes Red & Blue but the signs rotted away / got mislaid and were replaced by the painted arrows. The XC routes were fairly pants – sending you up this fire road then down the next and so on. This was all back when Beds Fat Trax ran the site. The routes became redundant after the last big tree harvesting which took away much of the established singletrack.
Have been in communication with the Chicksands Bike Park regarding the XC routes and they keep on saying they want to get some marked out but resources / money all dictate what happens.
Like you I used to make up routes taking in all the best bits.