If its commonsense to rig it, then just bring an inflatable doll.
The tests are to simulate a possible event and "test" your ability. In the case of equipment swap its a test of your problem solving skills and comfort in the water.
If these are things that aren't worth testing individuals on, then make your case and get the agency/agencies to drop those tests and you might as well just ask them to drop all testing since tests discriminate against those who don't try,practice or study.
It is not a test, nor is it a skill. It is a timed, stamina exercise (re: the inert diver tow).
The timed inert diver tow has little, if any, real world applications. In the real world, I would get the diver to shore/boat as quickly as possible while monitoring the person's panic level, taking care of injuries, rescue breathing if necessary, offering encouragement, gear removal, and trying to establish self-rescue techniques. Also, my pace would also be highly dependent on my distance from shore/boat, and whether or not I need to save energy for the exit. And I highly doubt that someone will be timing me while I take care of my victim.
Also, I do take issue with the four stamina exercises, and I have let PADI know. I can care less to know that my DMC can mask-fins-snorkel 800 yards in a given time. I can care less that my DMC can swim 400 yards at an Olympic pace. I can care less that my DMC can tread water for 13 minutes and then another 2 minutes without the hands in the water. I would glady trade the time spent on these for better, more accurate real world scenarios that a DM could be faced with.
The only thing the stamina exercises are good for it to weed out those candidates that lack even the minimum stamina requirements.
To show how silly these are...the DMC needs 12 cumulative points over the four exercises. I have seen each of these:
DMC #1 is naturally buoyant, but can't "swim". It takes the DMC 30 minutes to complete the 400 yard swim using some sort of lazy back stoke. 30 minutes is 1 point. Due to being naturally buoyant, the tread (which allows floating) was no issue for a 5. Surprisingly, the DMC can snorkel quite well for a 4. He only needed a 2 to complete the scoring on the tow which is less than 5 minutes. 20 yards every minute is very easy.
DMC #2 was a competive bodybuilder and triathalon contestant (ie like 0% body fat). Swim = 5, Snorkel = 5, Tread (sinker) took two tries for a 1. He only needed to complete the tow regardless of time for 1 point to pass.
Both passed, but who (#1 or #2) would you prefer to see as a DM just based on these facts?
DMC #3 gets to complete all of the exercises using a 100 yard pool/quarry (confined water conditions) versus DMC #4 that get to complete all of the exercises in a 10 yard pool. Turning chruns up a lot of time in these exercises. The DMC in the pool actaully has to work harder to acheive the same score.
What I found helpful was that he helped me with my fins and I helped him with his. We used two completely different weight integrated BCDs and there is a big difference in our sizes and shapes so we just made sure everything was wide open (straps) before hand off. We used a little extra weight but not much. The big help was practicing donning and doffing the BCD underwater. Once that skill and piece of equipment wasn't a challenge, we were good to go. 
