I hear you. But, the transmitters are attached to 1st stage regulators. Maybe the transmitters should be on the "annual 1st stage inspection/service" schedule, instead of the computer battery swap schedule.
Anyway, just idle discussion. Not trying to tell you what to do.
One question I would wonder about is that rechargeables vs non usually have a different discharge curve. My Atom allows me to actively check the battery status of any transmitter it is paired with. It will say "GOOD" or ... something else. I think the Perdix gives a more passive version of the same thing. I.e. it displays tank pressure and, if it doesn't display anything else, that means the transmitter battery status is "good". If the transmitter battery is low, IIRC the Perdix will display some indicator of that.
If you change the transmitter battery to a rechargeable, I wonder if that will throw off the battery status monitoring due to the (possibly) different discharge curve. I.e. your computer might tell you the battery is low when it actually still has a long way to go. Or, worse, when it tells you the battery is low, you only have minutes left before it dies.
In the face of this uncertainty, I (just me, personally) would stick with the "normal" CR2 batteries. My plan is, whenever my original one, on my original transmitter, finally gives me a Low warning, I will start replacing it and the one in my other transmitter annually. As you, I like to have things on a schedule. But, I also like to know what their limits are.
