The source XML contains CRLF between the XML tags so instead of the null tag looking line this:

<LFO></LFO>

It looks like this:

<LFO>
</LFO>

Is there a way to strip the CRLF for some fields in the custom data selection where the CRLF scenario would return a NULL ''? I thought of using the STRIP command but cannot strip CRLF and I though of reformatting the field to strtocur/curtostr (it is a monetary value in the source XML).

no dice.

You would need to use the Advanced Search and Replace plugin and have all CRLF found before a < replaced by a single <. You could use the following regex. Tested it and it works for me ) :

([\r\n ]+<)

and replace it by

<