Mbientlab Metawear Library

I’m trying to integrate the Mbientlab Metwawear library but it seems they are using dynamic_cast.

The compilation error is error: 'dynamic_cast' not permitted with -fno-rtti

I cloned the firmware repository and followed the getting started guide for self compilation.

I can successfully compile and flash the tynker application.

I’m thinking I can just remove the -fno-rtti flag but I’m not quite sure why it is there in the first place, and if its is strictly required?