Diazo overhead?

Diazo newbie question:

What's the typical overhead for Diazo to run a transform on a very
typical page in Plone?  I have not been able to determine this, and
have not yet needed to invest the effort to profile it against some
non-trivial theme.

In trying to understand how plone.app.theming (and
plone.transformchain) works, AFIACT it looks like there is no
caching/memoization of a transform result, even if the response body
prior to transform is byte-for-byte identical to a previously
transformed request in the same instance (not in development mode;
only the transforms themselves are cached, not the result).

All of this just makes me more curious as to what kind of overhead
folks using Diazo themes are seeing in the wild (page load time vs
unthemed)?

Sean

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