I once scheduled two other shops the same day I took on a typical (read: MASSIVE) hotel report. I am very detail-oriented and ended up having to pull an all-nighter and I enjoyed almost no elements of ANY of the shops to any degree at all. It may seem like a great plan, but in most cases, you are going to give yourself anxiety and pressure to the point that you'd be much better off just having slept in your car rather than subjecting yourself to the major undertaking that is a typical hotel shop. Speaking as someone who has performed more than 60 hotel evaluations, stacking shops is not a great idea for the bulk of standard hotel assignments. I have completed reports for ALL of the biggest chains in the U.S. You can't think of it as "one" report, really. One standard hotel report is truly more like anywhere from 10-15 reports rolled into one massive document. It can be a lot. Particularly if you are new to it. When you have done a few, they get a bit easier to plan and execute, but it is still a lot to manage. The reimbursements are usually great but the fees are usually less than 40 bucks or often just nothing at all.
On a positive note, there are some exceptions. The least stressful experiences I have had where you could easily stack on extra shops would be the Yogi Bear campground shops where you can get a glamping cabin (some locations are pristine, but some are super shoddy, so read reviews first!!) and then also a certain company someone "might have" mentioned earlier that gives multi-day shops, typically for timeshare audits. I have done those and outside of spending an hour dealing with the timeshare presentation and another hour or so to do your report diligently, you have the remainder of what could even be as many as 5 days all to yourself. Sometimes they put you up at a resort, but sometimes you are shopping the timeshare at a resort but they put you up at more of a glorified motel situation, so read carefully before you plunge. Mine have frequently included free tickets to waterparks, etc, and I spent practically two of my three whole days just floating on the lazy river with my shop long-submitted and not a care in the world. One of my favorite shops ever!!! So they are out there, but you have to be careful with what you choose. Good luck!