hmm and Smart Scan seems like has same option too ...
Nope, Smart Scan doesn't enumerate the folder structure at all, it basically scans just autorun entries end loaded modules.
also the setting is present for all the other Full, Quick, Custom except bootscan
And that's correct (if you mean the setting about the ordered scanning), that's where it has the biggest effect. Why Quick Scan has the option to follow links enabled, I'm not sure, it should be disabled in my opinion.
so hard to tell if they also negatively affected ;(
I think that basically the only scan where it may be somehow confusing is the Explorer Extension, and possibly the "Select folder to scan" one.
Now I think the whole thing is questionable... you select the C: drive to be scanned, so should we actually scan the C: drive, or also something else on completely different volumes? Some would choose the former, some the later. Sure, when the option is there, it should work... but I can also imagine a "solution" could be to remove the option and not follow links at all (one problem with following links is that they can end up in an infinite loop). I'm not saying I would like that solution... I'll see what I can do, but no promises.
p.s. note that those Junctions / Symbolic Links are usually leading to another drive which sort of invalidates the 'order of storage on drive' completely
I certainly don't agree with the first part
99.9% of the users only have the default system links - which lead to the same (system) drive.
Only very few users would have created their own links, possibly leading elsewhere.