Owning a Vacuum type veneer press, several as large as 72"x144" as small as 12"x12", bag and frame type. But they in no way replace the need for small manual presses like this.
I like your idea for this planer as a press, and it can be used for other stuff, not just veneer. I myself made a small press a bit large than your planer/press using a Shop fox press screw with a huge wheel and cast iron table saw wing. It almost looks like an old manual book binding press(those work for woodworking as well.).
Avacuum press is used not just because the amount of pressure, most times guys that are new to vacuum pressing veneers think they need full blast, they often use too much vacuum pressure, especially on some super thin veneers. The point of a vacuum press is yes a lot of pressure, but EVEN pressure is the key.
I like what you did, might even do something like to with my old Rigid planer. Its's a cool idea and doesn't have to take the place of a vacuum type veneer press at all.
Sometimes I'll make small letters than need go in a .25" deep pocket and they are tight. Vac pressure as much as it is just can never push/pull those letters in the pocket, but my screw press just like your planer/press sure does. So I use that, set the letters then toss the whole Assembly in the vac bag while the adhesive dries.
In other words you made a nice complimentary press for veneering and all sorts of other things.