The focus continues to be Rule 5 a iii, and in particular the part about shots directly to the front wall.
The image to define the no go zone for opponents is the front wall triangle. The three points of the triangle are the strike point of the ball, the left front corner, and the right front corner.
In a previous posting 3 examples of the front wall triangle were discussed. Please check/review the posting.
When the strike point is close to a side wall, the opponents are forced off the side wall.
(Figure 670a)

Although there is a gap between the ball flight to the right corner and the side wall, it would be difficult for an opponent, on the right wall, to avoid infringing on that ball flight. The opponent is essentially forced to retreat to a position behind the ball or get to left side of the triangle. This is an easy ball for the striker to hit any part of the front wall directly.
If the strike point were very close to the side wall that of course makes the shot more difficult for the striker. However, a well positioned striker can certainly make the return directly to the entire front wall. And there would definitely be no room for the opponent to be clear along the side wall ahead of the ball.
(Figure 670b)

Balls close to the back wall are more difficult. It is a good shot to put the opponents to a back corner to retrieve a shot. But again, instruction to referees is to assume that a well positioned striker can make a good return to the front wall.
Be clear though, Rule 5 does not deal with the ability of the striker to make a return. Rule 5 concentrates on the opponents getting out of the way. Strike point #2 is a more challenging for the striker. However, the opponents have no where to go along the right side wall. Clearing to the side wall behind the short line is not possible. Rule 5 does not support the idea that gluing yourself to the back third of the side wall is proper clearing. They must move to the left of the triangle.
(Figure 670c)

Strike point #3 is close to the back wall which can be challenging, particularly if the ball is tight to the back wall. From this central strike point there is lots of room to be clear of a front wall shot.
However, the opponents must also be clear of boasts. After pushing opponents to a deep position, they must be careful to clear so that the striker is forced to play the ball and not given the opportunity to relieve the pressure with a let.
Rule 5 interestingly does not make any mention of how the ball arrived at the strike point. It could be a simple cross court front wall drive, a lob that has come off the back wall, a Philly, or a ball that has hit 3 or even 4 walls before arriving at the strike point. There is no mention of which player last struck the ball. The history of the ball flight is important, but not for Rule 5.
The bottom line is, has the outgoing team cleared the front wall triangle and the front two thirds of both side walls. So sayeth Rule 5 a iii. It would be better if it stated the two side wall boast triangles.
It is easy to get all wrapped up in these triangles, however, in a match they have little consequence unless the incoming team requests a let. The referee is not going to stop play on their behalf.