I knew one pro player who did.
Claimed that it had great value.

He also tracked what he called "cause scratches."
Those were scratches where the horse was entered in another race within the next 6 days.

He said those were far more valuable.

Trainer scratches seem to be more revealing of trainer intent . Vet scratches reveal little positive info.

My tracks right now are FG and PRX. At FG, only one horse had been a vet scratch and it vet scratched again today.

IMO, the current scratch list is an example of incomplete information that can be misleading. For example a vet scratch. What was the reason for the vet scratch? Was the horse lame/sore during a pre race exam? This could be significant. Or did the trainer not like the race and tell the vet the horse didn't eat up and shouldn't run. Or does the horse have a fever of sorts?
While it may not be possible to categorize all the different scenarios an explanation such as sick or lame would help us evaluate the next entry. Sometimes incomplete info can be misleading.

I think it may possibly be helpful if fit into the time sequence. The scratch list is for 45 days. Let's say there's a vet scratch at 30 days and then no works. Or the works thereafter are shorter or slower. Could be a red flag.