Why 3 - Tile Advice

[average]

I have these 3 parts for my dewalt wet saw but I only use one of them and that's the middle part. What's the rest for.

 

[gamma38]

The one on the left is a large washer to stiffen up the blade for mitre cuts i believe, the right hand one looks like it's for holding something wider like a profiling tool.

 

[average]

The one on the left is a large washer to stiffen up the blade for mitre cuts i believe, the right hand one looks like it's for holding something wider like a profiling tool.

Why is it larger for mitred cuts? Is it to stop the blade wobbling. Is it acceptable to leave it on for straight cuts because it'll save changing it all the time.