The PXIe-54x3 devices support a maximum of 1024 steps in frequency list mode. This is significantly less than some previous arbitrary waveform generators due to limitations in the amount of on-device memory used to store frequency lists.
You can now change the digital gain on the fly on PXIe-54x3 devices. This means you can digitally scale a waveform while generating. The only exception is that you cannot change digital gain on the fly if the flatness correction property is enabled, as flatness correction requires digital correction coefficients to be pre-computed.