Quick question: can you install a Commlink (normally an Headware) in a Cyberarm?

As far as i remember: yes.
Cyberware either has an essence or a capacity cost.
If the Piece of Gear has a Capacity Cost, it can be installed into a Limb for no essence Cost.

Yes, it has a capacity attribute
It would take up 2 capacity.

I was asking because there are some pieces of cyberware that can seem... funny in some limbs.
Like a biomonitor on a cyberear...

Ears and eyes do not count.
You can only put eye-stuff or ear-stuff into these.
You can NOT put anything that is NOT eye or ear stuff into eyes or ears . .

Good point: it's *limb* capacity, not eye or ear.

yeah, but introducing several different kinds of capacity was still dumb i say . .
you don't want something to fit in there? give it too much capacity needed!
one capacity for EVERYTHING and eyes/ears simply get less capacity than would be needed to put some stuff into them . .
And limbs get less capacity than a vehicle. And Armor is somewhere in between . . as are glasses, contact lenses, goggles and the such <.<

I dunno about that, but they could certainly have handled the various flavors of Capacity much better. Eye, ear, cyberlimb, visual/audio sensor enhancements, sensor packages, armor mods… each of these has separate and incompatible 'capacities'. That's off the top of my head, there are probably more.

vision enhancement mods in a cyber leg. seems silly too though

Why?
You can get whole EYES in there . .
Don't tell me a Camera in a Finger or toe is silly enough not to allow it . .
Granted, there's basically no reason why anybody would do it, but still . .
Well, okay, so there's one reason . . filming up under womens skirts . .

That's not a visual enhancement mod, that's a visual sensor.