yah since it is the bank's responsibility to implement the guidelines, every bank will have different approach to it. I give you ideas and you share it at ABM meetings.
1. Ask card members to email their latest BE form. Those who email will get RM10 credited into their account. Benefits:
a. BNM cannot dispute this.
b. Save the banks money on paper, filing space, manpower (running to the fax, office boy moving files, fax misplaced, lines being congested as you mentioned, headaches when want to review or reconfirm as fax/letter cannot be traced).
c. Banks will also get credit where less paper are being used and show that they the bank do care for the environment.
d. Consumers can email at their free time and all will email because of the RM10.
2. To make sure all email, those who submit proof of income via fax, branch or post , an admin fee of RM2 will be imposed and make known to customers it may take up to six months to evaluate and pending confirmation credit limit will be automatically reduced to RM6K, hahaha.
3. ABM should suggest to BNM that people above age 40 ( retirees and pensioners) are not subjected to this ruling if they don't have 12 months consecutive outstanding balance. This is for my benefit

Or even extend this to all, so people that are responsible in their spending are not penalized.
4. Maybe all the banks contribute to form a new company that only specialize in evaluating customers for credit cards initially, after few years, extend the service for loans, etc. Consumers want a CC, got to even pay this company a nominal sum so that this company can be self-reliant.
If you guys thing my idea is beneficial, please do not hesitate to make donation to me

I am also available for consultation, hahaha.
Let say ah.. On one bad day, your employer decided to cut your salary due to some reasons. The bank won't know unless customer update the bank on their salary movement yearly.
The best solution is to link the bank system to Income Tax system.