DataMatrix inserts wrong character for FNC1 about zxing.net HOT 3 CLOSED

I'm not sure if it's true or, at least, it is commonly implemented/interpreted in that way.
I looked into the GS1 DataMatrix Guideline (https://www.gs1.org/docs/barcodes/GS1_DataMatrix_Guideline.pdf) which says at page 15 that the codeword 232 is used as start character and as field separator.
The GS1 General Specification (https://www.gs1.org/sites/default/files/docs/barcodes/GS1_General_Specifications.pdf) says at page 292 the following:

Use of FNC1 or the control character (ASCII value 29 (decimal), 1D (hexadecimal)) as a separator character following non-predefined length element strings.

It seems to me that the two symbols are alternatives.
You say that the 232-Datamatrix codes still passes verification. So I don't see a reason why it should be changed. But I don't have the Datamatrix specification document to read the full specs.

from zxing.net.

I agree that the GS1 DataMatrix Guideline does make it sound like 232 is the only use of FNC1, but in my opinion the ISO document is more trustworthy.
Here are the relevant sections

I also verified the 2D shown in the GS1 standard on page 221 and can confirm that their examples use 29 and not 232. Verification done using one of these.

I'm personally not comfortable producing a barcode that differs from the standard, from examples by the GS1 standard and from the firmware in commercial printers so I've forked the repo to add the change. I'd much prefer to just use your repo though.

from zxing.net.

changed the behaviour so that the codeword 232 is only added the first time when the GS character is found. any further occurence is added as 0x001d.

from zxing.net.