Clamps / clips for glass on heatbed
How about the Ultimaker clips? Ultimaker uses 2&nbsp;mm heat bed and 4&nbsp;mm glass, that should be within reach by bending the clips a bit. They have quite a low profile/footprint.



These clamps are very cheap and can be found on those typical auction or Chinese sites.

Alternatively, you can also tape the glass to the aluminium bed using kapton tape if you are concerned about hitting the binder clips. 

Note that e.g. in Marlin firmware, you can define a Z-offset to prevent hitting the binder clips on movement.