If both axis are moving at the same time they can't have different feedrates. i.e.
G01 X2.0 F7 A10.0 F70 = NoGo. You'll get the warning, "Multiple F words on the same line"
You could speed up the A axis Velocity under Motor tuning, I run mine (though a different style) at 6000 at times.
Not too much, you'll run into missing steps.
If the moves are on 2 lines, i.e.
G01 X2.0 F7
the Replace All feature in Notepad can easily go thru and edit the entire program for you.
Find What: G01 A10.0
Replace With: G01 A10.0 F70
You may have to do the same for G01 X2.0 F7 if the F7 is dropped later in the program