In the teller system, you can configure exactly how check holds should be calculated, including default hold days as well as calculated hold days by check R&T or amount. 
In both teller posting and ATM processing, the software also allows an Electronic Hold configuration that can be used in conjunction with a "Member in Good Standing" configuration. Different levels of hold times can be configured based on the 'Member in Good Standing' and also within the Tiered Scoring feature.
Using these tools the credit union can implement their desired Funds Availability disclosure.