@abonhote You may want to take a look at How many single key modifier/combination possible? - #6 by maexxx
I described there how to put various functions on a single key, depending on how long/often you press it.
The problem with ifDoubleTap is that on the first tap, it will always activate the primary (non-doubletap) function, and on the second tap, it will then activate the doubletap function.
If you want to skip any activation on the first tap (if followed by another tap within a timeout period), then you have to use ifGesture. This will introduce a timeout delay if you only tap it once.
Try this:
ifGesture timeoutIn 300 $thisKeyId final tapKeySeq capsLock semiColonAndColon capsLock
tapKey semiColonAndColon
You may need to set the keystroke interval to more than 0 in the Typing behaviour in Agent (I use 10), just so that the UHK produces a little delay between the scancodes in the tapKeySeq. Some host OS need this; some don’t.