Hmm, the Right way... no. But I have "stable" solution to put your own Create call instead of relying on the auto-generated one. The solution is quite simple (I've written about it somewhere but don't remember now where it was).
In the "extra code" of the root element (the wxDialog's one) put the closing block comment:
now in the source file add the desired Create call and opening block comment right before the initializing code block:
wxDialog::Create(...);
/*
//(*Initialize(SomeClass)
...
and the original Create call is now disabled-by-commenting
The only drawback is that it also comments declaration of local variables (used when item has "Is member" set to false) - so either all items must be members or you'll have to add them manually before the initializing code section.
After that you can freely work on the resource without the need to touch the code.
I know this is only a workaround. And from what I've observed, the customization of Create() call becomes more and more desired, so... it's on my TODO list now.
Hope the fix I've presented will be enough for some time, in few weeks I should start working on wxSmith harder than in past few months.
Regards
BYO