I freely admit to there being vast gaps in my X-Men knowledge so it's quite proboble there are at least one or two instances where he does KO a Brick or two, He's been able to floor Wolverine before now and has scrapped many a Sentinel but the power of his beams has waxed and waned a lot over his lifespan. I think as well he does hold back to a degree as it used to be the case if he focused his beams tighter the impact was magnified - I think it's Uncanny 124 where he considers how to stop Collosus and is reluctant to use a full power tightened beam as it would almost certainly injure Collosus.
There is a solid argument he has to be careful how he uses his power as otherwise a focused beam could punch right through his opponents.
The problem is that Cyke's optic blasts have never made any sense so writers have used them differently. They are most commonly shown to be some type of concussive blast rather than a laser or torch. However, we also see them bounce off of objects and become focused like a laser, which makes no sense given the last statement. Clearly, the ability to make his blasts more potent (like a drill) by focusing the beam has never been a consisent ability of his. Has there ever really been a clear explanation of what his power is?