ADMV1014 IF filter - must it be reflectionless?

Hello EZs,

I'm designing a PCB using the ADMV1014. I don't require a large IF bandwidth so don't really care about anything above 300 MHz, therefore am putting a low-pass filter on the I and Q differential outputs. 
My current filter choice (Mini-Circuits' LFCG-320+) is reflective in its stopband (500 - 6000 MHz) - what will happen when most of the output power at frequencies above 300 MHz is reflected back to the ADMV's I_P, I_N, Q_P and Q_N pins? Is this okay, or should I get a reflectionless filter?