RAM Frame and NBCC 2015 4.1.8.11 4)

Hi, 

Based on NBCC 2015 4.1.8.11 4) single storey buildings with steel or wood deck as diaphragms can have a higher fundamental period compared to 4.1.8.11 3) as seen in the snap below. However, in the current RAM frame the Ta is only based on clause 3). In addition, if I user specify the period, it gets capped out on the design as 2* Ta for braced frames from clause 3). Is there a way to implement this or make the user override the current maximum Ta limit? 

Thanks,