Flywheel movement when clutch depressed

[A7novice]

I don't think I have a problem, but thought I would seek advice/comments of more experienced A7 folks.
I have a significant oil leak from back end crankshaft bearing, into clutch housing.
As long as the oil keeps off the clutch, I am happy to live with this leak.
But, I have checked the flywheel, when running, if I depress the clutch, the flywheel moves forward by a tiny amount, about 0.5 mm I estimate. 
My query is, is this small amount significant, indicating a problem,  or am I worrying about nothing.

[Ian Williams]

It usually indicates a broken front main bearing flange.

["Slack Alice" Simon]

If the flange is intact, then movement is due to wear in the ball bearing or pair of ball bearings that locate the crank for-and-aft.

Or wear on the crank journal that allows it to move in the bearing - unlikely, and the movement would be greater.

[Ruairidh Dunford]

If your engine is fitted with ball and roller bearings, at the front of the crankshaft, it will always have some end float.

This is particularly noticeable with modern C3 bearings.