How to set mouse button to Ctrl in xbindkeys?

Question

linux

There is a mouse that has an (8) button (for example, I want another one on Shift) that needs to be reassigned to Ctrl, but xbindkeys only holds Ctrl and only when this button is released (does not work while holding), while after pressing its release, Ctrl remains as if clamped, until you press Ctrl on the keyboard again or kill xbindkeys. It should be like this: pressed the 8th mouse button - Ctrl is clamped (including using other buttons, the wheel, etc.), pressed - Ctrl is pressed.
~.xbindkeysrc

"xte 'keydown Control_L'"
        b:8
"xte 'keyup Control_L'"
        b:8 + Release

The presence or absence of Release does not affect the behavior in any way, the use of other keyboard emulators is the same everywhere. Mouse over wire.
The solution with xbindkeys is not the only valid one, if there are any other ways to rebind the buttons, I will be grateful for the information.

Answer 1

if there are any other ways to remap the buttons, I will be grateful for the information.

Easystroke
PS configured so on the mouse for one button - Ctrl + C, for another - Ctrl + V.