All pumps take "some" back pressure. Just the physics of moving water causes that. But, when you take 3/4 diameter PVC
hole and squish it to 10%-20% of the area, that's a different story.
Not that it won't work. Heck I've never tested this specific setup. I'm just pointing out a concern from an engineer's perspective. Again, some pumps are pressure rated for a reason. They are also engineered differently for those applications. Just something to be aware of.
I'd say go for it
. If it fails prematurely, you have your answer. If it doesn't, you have a successful design.