For the 44c, you might try this to get comfortable with the exercise as mentioned.
I'd call this approach the: "snap your fingers prep"
Before executing 44c, do a quick finger snapping exercise slowly (steps 1 & 2)
1) Hold up your strumming/plucking hand in front of you--thumb-side facing you, pinky facing the ground--and put your p and m fingers together in preparation to "snap-your-fingers". Do this as you would to snap-your-fingers in a traditional way, but just use p and m.
2) Snap the p and m fingers very slowly several times and pay attention to how the thumb and middle finger move and the X shape they make in your hand after snapping the fingers
3) Per exercise 44c, plant the 4 fingers (p i m a) accordingly, place a slight bit of pressure/weight from the i and a fingers onto their planted strings, but lighten up the pressure/weight of the thumb and middle fingers just a bit.
4) Remember the finger motion from snapping the p and m finger and the X shape they make, now try to perform the same motion and set the two strings into motion while i and a continue to mute their strings for two counts
5) Use i and a to set their two strings into motion and immediately afterwards, plant p and m onto their strings to mute for two counts
Repeat step 4 & 5 -- very very slow to build the muscle memory