You shouldn't be able to touchreverse if your WEVO shifter is adjusted correctly. Read the instructions and make sure the shifter is encountering the reverse lockout plunger inside the shifter. It should function similar to the factory shifter in that you must be clear of the reverse lockout mechanism by being in the 3rd-4th gear center plane.
https://www.wevo.com/Products/ShifterProducts/ShifterImages/WEVO_915_Shifter_INSTRUCTIONS_2009.pdf
If you look at how an original Porsche shifter works, it's a little bit clearer how this reverse blocking occurs and it's pretty simple how it does this. The lockout is accomplished with a spring loaded small teardrop shaped metal plate mounted on top the shifter housing. When the shifter is placed into 5th, the shifter lever encounters the teardrop and rotates it clockwise. When the shifter is fully into 5th gear, it will clear the tip of the teardrop, and then the teardrop is allowed to rotate back to its original position. Then when you move the shifter out of 5th, the shifter is forced to follow the shape of the teardrop. The teardrop is not allowed to rotate any further counterclockwise than its resting position and therefore the shifter is effectively blocked from entering reverse. Only when the leftward movement of the shifter has gone past the tip of the resting teardrop can the shifter go downward, and that is into 4th gear (or 2nd, God forbid.........
). At that point, the only way you can go for reverse is to deliberately move the shifter straight to the right and then pull downward.
The fore-aft play is not in the shifter linkage when you've got nice fresh bushings. The play is primarily internal to the transmission and there's really nothing you can do about it. The "slop" you feel is the clearance inside the transmission between shift rod dongle (nice word, I know) and the receiving block (s) on the shift rod, along with the clearance between the dongle and the support gate. There's also a bit of play in the area between the gear engagement sleeve and the brass shift fork.
Gordo2 here on the forum put together a very nice video of the transmission operations going on inside, showing you what happens when the main shift rod is operated by you the driver with the shifter.
https://www.youtube.com/watch?v=LLEWjNRjJTI
It's pretty cool how the forward-backward and side-to-side action of the shifter is translated into forward-backward and rotational movement to operate the main shift rod of the transmission, which only moves forward-backward and rotationally. This main shift rod translates the shifter movement into action that engages the gear selector rods for either gears 1st & 2nd, 3rd & 4th, or 5th & Reverse. Note how gears are paired with each other because they share a selector rod, which means they are adjacent to each other inside the transmission.
When watching the video, note that the slop you feel is the forward-backward clearance of the dongle when it is inside the block on the rod and the clearance of the dongle within the gate. In other words, note how there's a some clearance between the fat tip of the dongle and the "window" of the block when he rotates the dongle into the block. Later when he holds the removable plate in place underneath the dongle, you can see how the gate supports the dongle in its hole, which creates a pivot point, and that support forces it to move forward and backward. You can also see there has to be some clearance between the fat area of the dongle (where the hole is located) and the inside edges of the gate.
So there's basically three points of clearance:
-Tip of dongle inside the window
-Body of dongle inside the pivot gate
-Pivot point hole in the midpoint of the dongle.
All those clearances add up to make up the slop you feel and it's an unfortunate circumstance needed to allow those parts to move freely and not bind.
Plus the other thing to keep in mind is that this dongle movement shows how important that removable plate is. Most notably the gate itself. Unfortunately the weak point of the plate is actually where the gate mounts to the plate. The force of selecting gears is hinged on that gate and the three 6mm studs threaded into the plate to hold the gate can sometimes pull out of the plate and strip the threads- in hindsight it would have been good if the plate was made out of steel instead of aluminum. So make sure those studs are tight in the plate. In some cases the plate needs to be repaired or replaced. I found on my racecar transmission that the plate was drilled out for longer bolts that pass thru the plate. Plus the heads of the bolts were tack welded to the gate.
third gear squeal