When using Radio Test Library 1.20 with CC1352P connected with device id L42001YR the setParameter for txPower returns error when working in propriety mode.
It gives an error with the executable that comes with the library, but I also tried compiling it myself and changing a bit (e.g remove the PA use, change the output power value) and always got the error.
When working in ieee_15_4 mode or ble there are no errors.
Also, working with smart RF Studio, there are no issues and the power can be set for propriety mode (as well as the ieee_15_4 and ble).