It can't be done without modifying Tk. But if I do modify Tk in a way
that puts the results in variables, then I can pick up the results in Tcl and send them back to Pd, so that, in addition to [cputime] which measures only server time, you'd have a few more measurements, such as total time spent in Tcl/Tk, total time spent in the Tk part, total time spend in the rendering part of the Tk part, total time spent parsing, etc.
that could be interesting to measure tcl/tk efficiency and etc. For
example, once I had a data structures patch with gop, that took me around
20% cpu. I put it on gem, and it went to 0% - it wasn't a rough patch, but
I think the whole gop+graphics was taking too much cpu.