Do ED-E's weapons work in casinos?

I'm about to go meet Benny in his suite at the Tops and, frankly, I don't trust him to come alone and unarmed to our little meeting. I won't be arriving empty-handed myself - I've got a quiet .22 and a whole armload of grenades, but rule 1 of a gunfight is bring all your friends who have guns. Naturally, I thought of ED-E, who has them built in.

Can ED-E use weapons in areas where they are ordinarily prohibited, specifically casinos?

Yes. Ed-E's built in weapons are considered holdout weapons, which can be carried into a Casino. In addition, any human companion can carry any holdout weapon that the Courier's sneak skill will allow. So you can give a .22 to your buddy Boone as well, (for example).

However, according to the "bugs" section at the bottom of the page, ED-E's integrated weapons can be brought into weapons-free areas as holdout weapons only if the player's Sneak skill is below 50. This is caused by ED-E's weapons being included on the holdout weapons list but not the improved holdout weapons list.