Searching for the right plug

So here is what I m looking for (all in one or a combo of plugs)

The ability to write in realtime without time continuously moving forward.

When I play a not on the midi keyboard it records as the length of the note pressed. After letting go of the note it moves on to the next input but no further. The next input can be a rest that can be assigned to any key or lets say drum pad. That rest is recorded as long as I hold the key/pad.

I can have a set tempo.. lets say 90bpm. I hold down a C for a 2 count on 90Bpm and let go it records a half note. I hen sit and think. Ill have a quarter rest next. So I hold down the rest key for a quarter beat.

Similar to an audio recording device that starts when the mic pics up audio.

The beat always begins when there is an input. without an input it pauses. Starts again with input.

If there is a combination of plugins or one plugin that can achieve this please let me know.

If there are any questions on what I am asking please feel free to contact me.
reference Plugins Musescore in the subject.
I cant figure out why this is not just available.
Neal316@gmail.com