Application, please.
In every case that I know of that mandates restrictor plates, there's a rulebook that pretty much dictates the course of action.
Steady choked flow across the restrictor plate will set the max limit on the mass airflow and thus the power output. If the restrictor plate can be designed as a converging-diverging nozzle, there might be some hope of having the manifold air pressure above the choked-flow pressure ratio. It's usually going to be better to have a plenum between that and the engine to even out the fluctuations.
I have a 400cc 4 cylinder motorcycle engine with 60something horsepower and an airbox with an inlet snorkel whose minimum cross-section is somewhere in the vicinity of that size (I think it's a little bigger, but that snorkel is not intended to be a horsepower-limiter). A somewhat bigger-displacement engine tuned for mid-range torque may be able to make use of that over a wider RPM range.
Ruff numbers a 600cc 4 cylinder at 6000 rpm is pumping 30000 cm3/s and you've got about 5 cm2 so that's going to be around 60 m/s through the restriction, probably not enough to affect it much. At 12000 rpm it's going to be 120 m/s (nominally) and it's going to start noticing. A 1000cc 4 cyl the nominal flow velocity is going to be nominally 100 m/s at 6000 rpm, 200 m/s at 12000 rpm, that's going to be restrictive. You'll have to properly dig into the compressible-flow equations to get a more accurate estimation of the nozzle flow, and the cam timing of the engine is going to affect the VE. The engines that I've described are motorcycle engines that are designed to make power with revs, and the restrictor isn't going to let it rev, so it may be better off with milder cams.