Bad choice for an UI comparison...
Singularity (and Genesis, which is a fork of it) is not a "genuine" v1 UI viewer any more... The whole
llui library (i.e. the code used to implement the UI), as well as the keyboard management code have been replaced with a backport of LL's v2+ viewers (i.e. while these viewers are using a
v1-alike-skin, they actually are v2+ UI viewers)...
The Cool VL Viewer, on the contrary, is still using my fork of the v1 viewer code for the UI and the keyboard management. And I do not intend to change this...
Without the sources of the script you are using for the keyboard detection algorithm, it is hard to tell exactly what is the "problem", but given the choice of keys in the combinations, you might be encountering a collision with the viewer's own (and non-configurable) keyboard shortcuts...
I
might be inclined to provide a Lua function for sending key combinations to the scripts (you could then send those combos via a Lua floater of yours, for example, or via Lua side bar buttons), but I won't change how the viewer keyboard shortcuts do work...