I've had facilities pass SQF audits with regular glass in doors leading to production by covering the glass on both sides with clear contact paper (or other similar film). To help prove to auditors that there was indeed film on the glass, I put small colored circle stickers on the windows before applying the film, and the auditor can feel that the film is atop the sticker with their finger nail. I made sure the doors are on the glass and brittle plastic registers afterward, and never had an auditor have a problem with it.
If you have the money for more elegant solutions, you can go for it. But just make sure you can prove any of the fancy solutions you end up with. Keeping a receipt for that expensive glass window for all future audits could be annoying.