Hi @lukehafermann,
That was a piece I ended up not writing, so I didn’t dive into this.
The best way I can think of to achieve this is to use the Pitch Bend lane in Dorico. You might have to do some calculations in order to get the correct Hz value for A, though. This thread could be useful:
Another solution I can think of is to use a VST which has a tuning parameter that can be changed via CC (and for that it might have to be a VST with a Learn function).
Let us know if any of these solutions works!