How Do You Write Lead Lines For Midi Instruments

Pitch bend, as in “when I play my keyboard, each note I play is affected by the overall pitch-bend amount”. The amount of pitch-bend is equal to the position of the wheel.
Sample-based instruments, on the other hand, always trigger at their initial pitch value, and only then will they accept pitch commands. There is no “wheel” to set the absolute pitch of an sample-based instrument, no state to remember.

So I’m basically saying that these are two different concepts:
Sample based instruments = pitch commands describe the motion of the wheel (relative)
Plugins = pitch bend describe the position of the wheel (absolute).

And that improvements to the pitch concept could go both ways:
Sample based instruments could have a global tuning (absolute tuning ), as discussed in this thread
And plugins which already have absolute tuning could get relative tuning (but the missing standards would make it less than ideal)

Because this stuff is both simple and complicated?