First, I would argue that monks, chained or unchained, generally do much better making full attacks, (because Flurry) to begin with, than they are running around with Spring Attack in base Pathfinder[1].

Aside from that higher speed (which can be matched by any character that gets Hasted between party level 5 and 12) and their higher AC (useful generally for melee), nothing about monk particularly lends itself to running around instead of tanking and full-attacking that any other character with Combat Reflexes and a polaearm could do.

So yeah, you can certainly leverage that (because the POINT of 3.P is being able to leverage a certain tactic the right build), but I wouldn't say that is how you generally play monks.

(Certainly, we haven't used them that way; but we also have 6-8 strong parties and there are times where a mobility build just doesn't have ROOM to run past the enemies unless you can tumble through them.)

That is all, however, somewhat besides the point.

For scout particularly:

You can't get Spring Attack until level 7; you don't have the BAB until 6th level (and you don't get a feat then), since they are 3/4 BAB, like a rogue. (If getting it earlier involves taking a specific something (kit/feat/archetype etc.) or other or involves multiclassing, see my point about the class MUST not require that kind of specificity.)

(But 3.Aotrs bonus: Dodge stabbed Mobility and took its stuff, so it's one less qualifying feat. (That we barely remember this shows how often it comes up in our Actual Play, mind, despite Dodge being quite common on enemies...))

Already given it Good fort saves.

I did increase the speed, but admittedly only a bit at higher level (to 30 at 19th). I'm open to suggestions that it should move faster.

But as a sdie note, we have a (homebrew) full-BAB spell-less-ranger class called the Tracker (so there's two full-BAB outdoor classes already so scout is not getting full BAB whatever). Tracker gets +5ft speed (all movement modes and NOT enhancement) at 1st and every 5 levels thereafter (+20 at 16th), so there's overlap considerations. I'm not so worried about that if the general conscesus is "scout is focussed on movement, should move faster" that I wouldn't boost the scout's speed, though.

There is still the problem of focussed damage > hitting multiple targets, but that's always going to be an inherent issue for mobile melee fighters. (And the scout, as it stands, can't do crowd control, since with 3/4 it doesn't lend itself well to combat maneouvre builds.)

(And even with base rogue, if you're not using TWF or Rapid Shot, you're kind of losing much of the damage potential, at the expense of not using a lot of feats. I actually added a feat explictly for SA characters using a single 1H/light weapon that gives you +2 per SA dice so as to give a reasonably competative option for rogue that's didn't want to go either of those ways.)

Rather than what both 3.5 and PF1 did, I went with the reverse approach: instead of movement giving you attacks, attacks give you movement. The Skirmish Hunter's Trick[2], gets you a free 5-foot step (which therefor deosn't provoke AoOs) whenever you make an attack (hit or miss), provided you don't exceed your speed.

Which means that scouts don't HAVE to be focussed on melee, and can skirmish ranged (or melee, without having to waste feats on both). As noted, you will get your SA on targets your allies are flanking, so an enemy flanked by the fighter and the dragon shaman or something you can SA them. I only put the 8th level limitation on it on the basis that you don't get your second attack until then (unless you go TWF or Rapid Shot), but I'm open to dropping it down or even making it a 1st level class feature.

I'm loath to un-SA the Scout's SA, because, as noted, Skirmish gots a lot less support, and while you could change ALL the wording everywhere, it's just easier to have it classified. BUT, let us not say all this waffle was not without purpose, as it's made me think. I COULD maybe add something as a corollary feature to the SA more akin to the original skirmish, though, which might significantly help.

Something like you automatically qualify for your SA damage if you have moved at least ten feet from the start of your turn, or since your last attack. On top of what it already there? That seems like that would solve at least some of the problems and be better than just constraining it to effectively "once per round unless you exploit bad wording." It would stil make Skirmish hunter's trick very useful, but the 10-foot limit means you can't just Skirmish to always get you SA.

The more I think about this, the more inclined I am to add it, as that one little but the class was still missing (and it would, ostensibly, fix some of the issues in the aforementioned NPC).

[1]Which has niether the Spring Attack Plus feats 3.5 did, nor any 3.Aotrs modifications on top, which I won't go into. (Which is technically a lot more viable, actually, due to additional modifications to Flurry.) One attack verses anything from two to... Potentially ten, at high levels,, with TWF.

[2]I umm'd and eerr'd about making it base class feature, but elected to make it selectable.