I watched an episode lately that involved the murder of a mom, who had an estranged husband, a boyfriend and a love-struck colleague. It went cold for many years. The body was found, but like Cheryl's, her remains were too degraded to determine how she died.
Husband was finally cleared; so was boyfriend. The love-struck colleague ended up being the one they focused on, based upon a neighbor witnessing him walking home (within a mile) from where the victim's car was left. (Sound familiar?) He also left out pertinent details in his interviews about seeing her that day. BUT there was no forensic evidence pointing to his guilt.
Prosecutors asked themselves if "waiting" would yield any more information. They decided "no" and proceeded with charges because it had been many years (Willing to roll the dice). They charged this individual with 2nd degree murder, he took a plea to manslaughter, and they avoided a trial altogether. He took the Alfred plea, and was sentenced to 4 years in prison.
This is the position LE is in in regards to Cheryl. IMO If they wait, I doubt no new information will come forth to solve this.
The victim's family in the above case, although sad that he received so little time, was grateful to LE to pursuing anything at all.
I wonder if Cheryl's family would feel the same.