A time to mow low yes or no

In the battle I wage each spring against pretty yellow flowers---oxalia---in order to keep my lawn organic and yet a lawn, I have had to break the rule of thumb and mow low. Reason being at this spring stage the faux clover otgrows the grass and my fescue is light deprived, yep buried in a miniature cudzu like world. Tell me I'm wrong but If my role is to give my turf an advantage, seems like let there be light should be the goal until the grass growth speeds up and the oxalia slows down. It is still to wet and cold---for the grass and conditions are optimum for growth of the pretty weed. As the soil dries a bit, the grass will have more advantage.

Sounds smart to me.  Although not very lazy. 

Grass usually keeps a HUGE reserve in the roots for the big spring push.  I bet it will be fine in getting a start in the spring even though it might be "buried" by other stuff.

Cutting low, or scalping to get at the weeds seldom has a positive effect, in fact once the grass starts to grow if it is done then it will actually stunt the grass growth and give the weeds a better chance to establish.

Mowing higher means that the grass blades will shade out ground. Oxalis needs light and low nitrogen (It fixes its own nitrogen from the air). Fertilize by leaving the grass clippings and mow high. Also, watering deeply less often will help because the grass roots will grow deeper. Oxalis just send out runners on the surface.