FWD cars should be rotating cross-to-front ;-)
For your driving and car it's working for you then by all means stick with it, you probably also have a decent alignment guy.
The vast majority of people complaining about uneven tire wear never rotate nor align their car on a regular basis, nor have they rotated cross to front.
Cross to front and diagonal are both accepted FWD methods when the rear of the car, however, every corner has a different wear rate so if tires don't make the rounds they'll likely still wear unevenly.
http://www.randomuseless.info/tires/tires.html
Check the 2nd graph where the wear rate of each corner was plotted to show what would happen if no rotations were done.
Cheers!
What you should be looking at is the time each tire has spent at each corner, you want them all to be equal in each position, not just the starting point and where you are now.
Uh so let's talk this out and follow the tire that starts in the left front:
LF
1: 5,000: Front-to-Rear
LR
2: 10,000: Diagonally front-to-rear
LF
3: 15,000: Front-to-Rear
LR
4: 20,000: Diagonally front-to-rear
LR
It's only ever been on the left side because you're skipping flipping 1 axle left-right by the alternation method you're doing.
So do the cross-to-front every time from now on so you'll achieve what you desire.
And you do now see that you're skipping the left-right flip for two, or in another light- half, of your tires?
Look at post 94, that tire doesn't leave the left side of the car... They are NOT doing L-R