Collecting under Reg B for HELOCs shouldn't be that big of a deal. GMI is only required for HELOCs under Reg B if it is "an application for credit primarily for the purchase or refinancing of a dwelling occupied or to be occupied by the applicant as a principal residence, where the extension of credit will be secured by the dwelling". As HELOCs are often equity loans (and not for a purchase or refinance), then GMI is not required.
That said, you will have the rare loan that is for a purchase (or refinance) where you need to collect it (though you technically don't need to collect it under B for a refi where you already have it on file from an initial purchase).
The link TMatt87 provided is the citation for all of this.
Adam Witmer, CRCM
All statements are my opinion, not those of my employer, and should not be taken as legal advice.www.compliancecohort.com