Hi Hugh-
I don’t have HOWR, but do have HOSP & would hate to know that I could’ve done/tried something if an attack ended up occurring. I would install it & stick around to see if she’s still entering after you install it. What’ve you got to lose in trying? Others that have experience with Wren guards may have more to offer you.
Deb-
Again, hopefully someone else will comment, but I’m thinking that you should leave that hole open to keep the wrens busy as you said. I would be afraid that plugging it could lead them to the EABL box since you don’t have the wren guard up. Just my thoughts…
Nicole