I'd say ADV scouting goes out the window much earlier, probably around age 23 with a few minor exceptions. By that time players are near who they will; though diamonds can change that slightly. They might gain a point or two in 1-3 categories from what I've seen but the improvements greatly flatten out and you pretty much know who you are getting. For your own farm system you can see the yearly progress and see how the curve has slowest. Some people depend on their draft scouting, you might jot down those scouting reports in the players notes rely on them over Adv scouting. The harder part is prospects you might be trading for. But you can use their age, pro years, and knowledge of when they signed (draft vs ifa) you can get a decent grasp on who they will become. If you are looking at who signed them for example; you probably have a good idea on what that owner's typical budgets look like; do they save enough for decent scouting to know who they are drafting?
In one season, the guy who had the #1 pick was on a quick rebuild and I doubted the prospect he picked because I figured his draft scouting was low as he was still running big player payroll budgets from contending the previous seasons. Court is still out, but he's looking like an SP4 versus the SP1 or SP2 that he was drafted asl.
Good luck!