Minimum RMS mount glass thickeness?

[WilRams]

Thinking about trying a G4 XR30 Radion on my IM Lagoon 50. The easy solution would be to mount the light with a RMS tank mount. My concern is the weight of the light on the glass. Im sure I'm overthinking it as glass is stronger then one thinks. The tank is 10mm thick (.39). If it was 1/2 I know I wouldn't even question it and go right ahead. So whats the verdict?