Hi,
The main issue with the W3PM based design is the usage of fractional-N mode for the correction of the Si5351a output frequencies.
There have been several discussions showing that a clean output cannot be realized when using an Si5351 in fractional-N mode (as required for the frequency corrections with this design).
An Si5351running with integer mode is able to generate 25MHz and 40Mhz with a signal quality that is good enough for QO-100 operation.
73 Jean DJ0VL