yes the use of ballscrews will almost entirely eliminate the chatter associated with backlash. Once you have the ballscrews in place you can mill in both directions,1/2 inch endmills cut .503 slots, in fact I do all my cutting as climb milling, condition where cutter is pulling the work into itself, which is something you cant do with acme screws. Gives a very smooth finish since the tool is always pushing away from the work instead of gouging inward.
The 5/8 ball screw and nuts are abut right for most of the table top mills $1.25 inch, nuts are about $24. I am using the 3/4 on my 14x40 lathe.
my bridgeport clone has 1.25 inch screws .2 pitch.One of my dads bridgeports is using the 1" from mcmaster with no problems. With the cheap nuts and screws, no preload I have a machine hear in use for 2 years less than .001 backlash, but usualy the 5/8 runs about .0015 backlash.
The only downside of manual machining with ball screws is you have to lock the axis your not moving as the table can be pushed and the screw will spin