I used to set baudrate to 9600 Baud (maximum) for software UART, especially on NRF52 platforms. For hardware UART I thought 115200 baud was still fine, but never really tested on NRF52, because it only provides 1 HW uart and I prefer to keep it as a console interface when BLE is disconnected.
I would recommend not to go much higher than 9600 Baud on NRF52, unless flow control is implemented.
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I used to set baudrate to 9600 Baud (maximum) for software UART, especially on NRF52 platforms. For hardware UART I thought 115200 baud was still fine, but never really tested on NRF52, because it only provides 1 HW uart and I prefer to keep it as a console interface when BLE is disconnected.
I would recommend not to go much higher than 9600 Baud on NRF52, unless flow control is implemented.