Yes you can but when you refer to either end that means on one end only as you can't have two dimmers in line on one light.
Obviously when the dimmer is set it will only switch on/off at that level of dimming. but I'm sure you knew that.
Yes have come across these, but only as a customer had had them put in by a "kitchen fitter" who put 5x 5.4w LED's on a 60-400w dimmer!
They couldnt work out why they had disco lighting in the kitchen...