Possible way to find workaround:
I tried to create workaround using remapping with AutoHotkey but succeeded only when I simulated also the layout switching which is not elegant.
Here is experimental code that works on my laptop Thinkpad X220 with Windows 7 when English and one more layout (e.g. Russian) are installed and the second layout is active. Not practical yet, just for playing around:
; # AutoHotkey script restricted to Obsidian
; comments are after semicolon
; ` backtick is default escape character
; ^ stands for Ctrl+
; + stands for Shift+
; ! stands for Alt+
#IfWinActive ahk_exe Obsidian.exe
; remappings to fix hotkeys from Russian layout
^sc023::
sleep, 444 ; intentionally large for observing, not for practical use
Send, {LAlt down}{LShift down}{LShift up}{LAlt up} ; Switch layout
sleep, 444
Send, {LControl down}h{LControl up} ; Ctrl+H
; SendPlay, ^h ; Ctrl+H
; Send, ^{vk48}
sleep, 444
Send, {LAlt down}{LShift down}{LShift up}{LAlt up} ; Switch layout
return
#IfWinActive ; end restriction to Obsidian
To make it work from any installed layout, there would also need to be keyboard-layout detection.