Disable Wincompose on hold

[eugenesvk]

I'd like to have tapAlt tapj start a compose sequence with j
But then holdAlt tap j to use my AutoHotkey-rebound cursor movement ↓
It seems that WinCompose always fires on key down
Instead I'd like to be able to fire it on key UP but only

• if no other key has been pressed between the key down and key up
• if no more than Xsec has passed between the key down and key up (in case I want to use the cursor key, hold holdAlt, change my mind and release Alt)