Hello,
On the UART side. We recommended DMA for communication during RF in 1.2.1. While RX worked well with DMA, the TX had a problem in that the last char might not always get sent. The solution in 1.3 is to use DMA on RX and ISR on TX. This has proven robust for customers. The HALT_DURING_RF_DISABLE will also work, but will increase power consumption some during RF - about 5ma. If you are using short intervals and running short on MIPS processing power, then the HALT_DURING_RF_DISABLE will help.
BR,
-Greg