What? Ctrl/Shift Insert is supported basically everywhere in Windows, from the lowly Notepad to the behemoth that’s Microsoft Word. Browsers support it. Terminals support it. On Linux all Linux apps I’ve tried support it. Even Emacs which famously doesn’t support the usual C-c C-v supports it (mapped to kill-ring-save and yank). This is as universal as possible in the world without Cmd key.
In fact the last time I bought a keyboard I made sure the keyboard mapping can be customized so I can actually put the Insert key on it.