Saddle height will just depend on where you want your string action set, which is dictated by neck angle, neck curve, how level the frets are, so teer is no recommended height, they end up where they end up!

I normally try and go for a nut slot angle that's halfway between flat and the angle of the string as it runs up to the nut. It's all a bit approximate, so don't worry too much over it. Just a bit less than flat will be fine.

Before you cut the nut slots quite shallow, you really want to set up the rest of the action first, or you could end up with string buzz on the first fret.

Stick a capo on the first fret, or tape the strings down hard if you don't have a capo. (If you don't have one I'd get a cheap one as it is very useful for guitar setups or keeping strings wound on the headstock if you have to take the neck off a bolt-on guitar to adjust a heel-end trussrod etc.

this is how I set up my guitars for a low action:

Set up the truss rod so that the neck has a very gentle curve in it - not much relief at all.

Then look at the action from the 12th fret and above. I then adjust the saddle height so I can just fret and bend all the strings cleanly. I normally start low and work up the action until I can bend the lower strings without choking and generally just do teh upper strings on clean sounding.

Then look at the action at the lower frets. Using the capo has taken the nut slot height out of the equation so you get a good idea of what's really happening. Do all the notes sound freely without buzzing? The action at the 6th/7th frets may still feel feel quite high. If so, tighten the truss rod slightly, maybe 1/16 to 1/8 of a turn. The neck will be flatter and the 6th/7th fret action will be lower (also at the upper frets but it's the lower frets we're interested in at the moment). do those low notes fret and bend cleanly? If so, you could try another very small tightening of the truss rod. Repeat until you start to get buzzing or choking on the low frets and then back off the truss rod slightly until this stops.

Go back to the high frets and test them for choking and buzz. Straightening the neck will have pulled the strings nearer the frets, so you'll probably have to raise the saddles slightly by a small amount. Once those upper frets play OK, then that's the time to take the capo off and file the fret slots. If you file them when the action is high and then lower it, you'll probably end up with 1st fret string buzz, so it's important to only do it once the rest of the action is sorted.

Filing the fret slots will bring the overall open string height down lower, so you should end up with a very low action (unless you have any rogue high frets). This may end up lower than you like, so then raise the saddles or even loosen off the truss rod slightly - but at least you will have the nut slots properly cut with no danger of the strings buzzing if the guitar action is later lowered.