I think it's an important and legit question. From the little I've used one I know it's slow. It's supposed to be more effective on thick layers of paint. I posted a link to an article previously that detailed that tool plus the paint shaver and Festool RAS115 & Metabo paint shaver. I think Tom O'Brien wrote it. You should be able to search this site or google it. Good article. It was published in JLC.
I typically figure 10sf/hr for stripping including the follow up sanding but that not with the infrared.
I would never bid that other than T&M.
In the OP the author was listing quite a few different types of surfaces (windows, eaves, gutters, shutters, doors) on a large brick building. I wasn't trying to be a dick with my first response, only making the point that I think that anyone sitting at their computer reading what he had to say would be hard pressed to give accurate
production rate numbers that would truly assist him. In addition, he appears to be unfamiliar with this type of paint removal process. Add these together and you have a scenario where he could really get himself in over his head and lose his ass in the process.
I would completely agree that bidding this T&M would be best. If not that, perhaps enlisting the assistance of another painter with experience in this type of work to assist in bidding and even helping out. Or a third option might be to try and get permission to actually do a few different areas on the building to get a feel for what will be involved. Then he would have a sound basis for working out a bid. Any of these would be better than taking numbers someone here might give him and trying to make them work for what he is facing. Heck, even declining to do a bid at all would be a better option IMO.