Spatstat: Residual analysis for Thomas cluster processes

Hi,
I wish to test the fit of a homogeneous Thomas cluster process,
ideally using residual plots like diagnose.ppm and qqplot.ppm.
Since the most straightforward way to fit a Thomas cluster process is
using kppm, I can't use the above functions. Can anyone suggest ways
to do this?
e.g. transforming kppm to ppm or using ppm to fit a Thomas cluster process,
Many thanks
Emily