Question about Field Modifications to Wood I-Beam

-During a Phased Inspection, I noticed that the builder had either ‘cut’ or ‘enlarged the cuts’ in numerous wood I-Beams so he could run HVAC flex duct through them. In my report, I stated that ‘Field Modifications’ are ‘not allowed’ to Wood I-Beams. (The holes were ‘not’ pre-defined knockouts)
-The builder responded that “it is only the middle third that cannot be modified”. I do not believe he is correct. As I see it, the corresponding IRC code reference is 502.8.2, “……or I-joists are not permitted unless the effects of such penetrations are specifically considered in the design of the member.”
-Am I correct, that this means NO field modifications are allowed on wood I-Beam Joists, regardless of ‘where’ they are in the joist span.?

Field cuts are typically allowed. Check with the specific manufacturer and keep the cuts within their specifications.

For example, see page 1:

I agree with Larry.

PS… Welcome !!!