Based on the way the saddles are shaped I would think you would want them angled back. The portion of the saddle the string passes over has a flat spot to it (maybe 3/32"). By tipping it back you are giving it a narrower point of contact. I suppose going all the way to flat wouldn't hurt except for possibly more side to side string movement, but if you tipped forward you would be changing the intonation. I'm not an engineer, but some sort of thought must have went into the guidelines of how to set up the bridge.
You don't want your contact point sharp as this can easily lead to cut/broken strings. It should optimally be rounded. Your intonation point is flawed as you would intonate the saddles position, not whether it's tilted or not. Intonate flat, then tilt? Yeah you're going to be off. Intonate tilt then set flat? Guess what.
Another issue with having them tilted is you're altering the string force into a more forward motion (pushing from more towards the back of the saddle than center) than more downward when flat. This means that if your set screw ever comes unknowingly loose, your saddles are going to be more likely to start to vibrate forward, pushing you sharp (fretwise tuned/flat open string because of reduced tention). Tilted back the downward force is not evenly distributed to the bridge plate.
Someone at Spector thought that the bridge saddles looked better with the string coming off the saddles at even angles (peledog's are actually further back then even Spector recommends, so his issue could be compounded).
This would be a fine theory if the bridge plate underneath were at the same angle as the saddle. It is not obviously.
It's funny how no other major bridge manufacturer (including Spectors new alternate/US bolt on standard bridge maker Hipshot), including Spector themselves with the in your face obvious, non-tilt adjustable intonation bridge, recommends anything like this. Hmmmm.......

There will be no side to side issues either way.
This bridge, except for having great high mass, is a caveman like, extremely limited design in this day and age. It was innovative in it's day for it's mass, but has been showing it's age for a couple decades now. I wish they would just go with all Hipshot "A" bridges and put this one out to pasture. It might bring in some newer players that look at Spectors as "80's basses" for more than just image reasons.