I´ll tell you why... first of all, not all have an ia10b, and, if I´m not wrong, both of these receivers have a limit of 2s lipo batteries, or 8.4 volts. If you ever read anything about electronics, you should notice that 12.6v is a lot more than 8.4. Since we appreciate the value of our money, we try to get the same result without burning our receivers down. And, creativity is always awesome.
Speaking of which, as I said some time ago, I have solved my integer voltage by using the hardware tx and rx plus a diode, but because of that I couldn´t read the channels (the library needed hardware pins) ad have only one serial port, I needed a soft serial reader (and I couldn´t find any). My Mega-based APM can only read 8 ppm or pwm channels (no IBus or SBus), and I still have 2 channels left that are available through IBus on the ia6b. In other words, if your board is IBus compatible, don´t waste on the ia10b. I just finished making a SoftIBus reader using a hardware based library, after a long time tweaking everything and getting the "error compiling for pro mini...". Project´s almost done!