deadlifts +20rep squat on same workout?

I'd say it probably would be too much but if you want to be a guinea pig and try it out I'd love to hear the outcome.
If you're doing true 20-rep squats, adding them in after deadlifts will increase the necessary recovery time exponentially. Unless you're some sort of Superman, your back will be F'd.
The whole point of the 20 reppers is that it should be very difficult and taxing. Watch any real 20 rep set and you'll see how difficult it is. Its not meant to be some housewife cardio kinda thing.

If you can do Deadlifts after a 20 repper, youre not using enough weight.

If you can do 20 reps after a Deadlift session, youre not using enough weight.
I also advice against doing this.
Also the question is what you expect from this.
Do you want to iron your form before your single session?
I usually do only front squats but had once a 20 rep workout. This week I did my first PR on backsquats which I never did on low reps on high weight. My form was awfull compared to the high reps session. I better had prepared on higher weights. 20 reps light squats won't help you on your singles in my oppinion. Especially when you fucked up your back on dl before.
ok thanks guys, i expected to get these kind of responses so ill follow your advice and skip it.

ill probably do something like this instead,
squat(light for reps and warmup)
OH squat
Front squats

squat 5x5 DE effort
OH squat
pullups(if my shoulder feels ok)

squat 1rm max.
OH squat
Front squat

i usually go the gym about every 3-5days so that
It sounds like a bad idea to me. I used to mix squats and deads in the same workout and eventually I came to the conclusion that it just wasn't meant to be. I do them seperately now. Give it a go and see what happens but rather you than me.
I'm currently on a 20 rep squat plan and this sounds absolutely miserable to me. For me anyway, the 20 rep squats really hit my lower back. I'm planning to try a DL max after I finish the program and see if the 20 reppers helped.