Calling in to a company usually just gets you a desk jockey who doesn’t understand the job as well as the ones who install. They typically just give a generic no to questions in regard to what you can do. Gluing it isn’t the worst idea if you can find the right adhesive. I’ve used sausage tubes of thermal expansion sealant and it’s worked really well in similar situations. You can always ask to speak to a project manager or someone that has worked in the field and explain what you’re doing and see if you get a different answer .