My opinion (because that was what was asked) is that a 3 week ME progression is good for a beginner. It's also my opinion that your squat and deadlift look pretty decent at that weight.
Really old school Westside was: stick with a ME exercise for a few weeks trying to break your previous weeks best. If you fail, switch to another exercise. I think this is much better than alternating ME exercises every week like alot of beginners are doing now.
Alternating every week is fine for more advanced lifters, however; it's my opinion that beginners should experiment with ME exercises to find out which ones work. If you are running an 8 week training cycle, this could be 3 ME exercises instead of 8...if you do 8, how are you going to know what contributed to making you stronger?
I've always felt that the squat and deadlift are close enough in muscle groups that deadlift ME or squat ME help each other out.
There's probably not a week that goes by that I'm not doing SOME TYPE of deadlift...that doesn't mean I'm pulling a max deadlift, but I am doing say stiff legged deadlifts off of a box or something along those lines for higher repetitions.
I hope this helps you brother.