Yes (5 handicap here). two tees in the ground 12 inches apart, one where the ball is - and see if you are coming 'inside' or outside the 2nd tee when you pull back and then look at your stroke forward - usually if inside, we rotate our wrists too much to correct and go left (though if we hold up the wrist break we can pus), or vica versa. So work on bringing the putter head back straight.
The other thing that you may be doing is decelerating rather than accelerating.....that can put spin on the ball and push right, just as with the swing. It is also the same with snooker, (I played a good level at amateur on that) and you see so many people not going through the ball with the cue and/or lifting their heads. Same principle at golf.
By the way the top exercise is great for iron shots/drives as well though widen the tees or use a club. I used to naturally fade the ball but got taught to come slightly inside to put more draw spin on the ball which lengthened me off the tee and with the irons considerably.....and then to have some semblance of shaping the ball either way on demand.