I dont do it that way... if you want some added weight raise the opposite T-bar... since they are wider than the frame I weld a piece of steel on the frame so they dont hang over and weld them directly to the frame
I would say any time you can gain adjustability it is a good thing. bolting your slider would not be much more work and give you some options. then you would have 4 corner adjust.
If you want... to me its just another thing that can go wrong..... JMO... your the only guy I heard of that bolts them on... but if it works for you keep doing it
