All depends on required freq, bandwidth. Using PWM will severely lower useful frequency.
One way of amplitude adjustment is hardware multiplier (see the YouTube for project link
This multiplier pairs well with DDS24 frequency generator
Another way to adjust amplitude without loosing bit resolution is to make R2R DAC out of 0.1% resistors, connected to SIO pins (for example port 12 on KIT-059). Such DAC works better than IDAC8 at high frequency. The SIO pins offer special mode, when output voltage can be controlled by the Vddio in range 0.5 - 5V, Depending on application, this might be sufficient. The Vddio can be adjusted either by using a DAC or PWM.
thank you for those links. I think I'll dig into the hardware multiplier approach, it sounds promising. I want to keep the DFB block clear for now, I want to use it for filtering CapSense input (already made some experiments, but the output of the DFB was not what I expected - another thing which I've to dig into).