Sorry it's taken a while to get back to you.
If you're still having difficulty with this, you could try and create a custom category that overrides our call to fatalLogMessage: fromSource:
This is the implementation file similar to what we use internally to stop the chart aborting during our Unit Tests:
@implementation ShinobiChartLog (DontAbort)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wobjc-protocol-method-implementation"
+(void)fatalLogMessage:(NSString *)msg fromSource:(id)sender
#pragma clang diagnostic pop
//Throw NSException, rather than abort();
@throw [NSException exceptionWithName:@"Generic Chart Exception"
I hope the above is of some help.