In principle, what you say is correct, however I have about 200 or so dives with double grey transmitters and have never once had any signal loss. Since they both have (in theory) the same frequency, if they are offset a little, say by starting one a second after the other, then they should never interfere as they will be always out of synch. However, manufacturing tolerances being what they are, if they are on different period then they will get closer and closer until they overlap, then diverge again. They will not need to be reset, as the computer will not recognise the overlapped signal as anything but noise hence the "lost Tx' message, once they diverge again it will be back to normal.It doesn’t mitigate the problem. It is a hack that may work sometimes but the problem is always there. Should you jump in and the transmitters are "in sync", you’ve lost pressure info and will need to "reset" one underwater.
With two different colours— the yellow Shearwater one plus one other such as the Aqualung or grey Shearwater, or the new Shearwater one — the problem is eliminated.
Your choice.
My choice was to pay a few bucks more for different colours and not have problems.
I am sure I probably did have a moment or two of signal loss before, but never while I was looking at the screen.