With kids around, who might unplug things and look into a 1320nm beam, multi-mode seems safer.
Why.... would there be any difference?
On a low power <1km optic, the danger would be about the same.
850nm MM transceivers are NOT safe to unplug and look into anyway.
That's like saying you prefer to drive a Diesel vehicle instead of a Gasoline one, because your kids like to play with matches next to fuel spills.
I mean...sure? Gasoline flashes far more easily...but neither is remotely "safe".
Note: LC connectors are pretty stiff and spring loaded. They absolutely should not be easy to disengage. They certainly aren't child safe, but a kid isn't going to accidently or casually uncouple one. They would really have to squeeze down on it. By the time your kid has the manual dexterity and hand strength to open one, they are probably old enough to understand that unplugging one and looking into it is dangerous.
So I suppose there must be some combination of a 2-year old with gorilla hands that can open child safe bottles, but you still need to lock your kitchen cabinets because they can't be trusted not to drink the bleach you store there?
I'm not going to tell you now to protect your kids, but if you are genuinely worried about this, you probably have a LONG checklist of other child safety things to do first before this is even remotely the worst threat.