You can change the tuning of HALion and other synths. Doing it for each track sounds OK if you don’t have too many tracks. What I’d like to point out is:
The tuner plug-in can be changed to define A as 432Hz.
To do this, go to where it says “Base: 440.0 Hz” in the upper left corner of main display (digital mode).
Then double-click on the 440.0. It changes to an editable field! Enter 432, and you’re good. Now you can tune your violin/guitar/flute/bass/saxophone/etc to equal temperament based on 432, or the love frequency, or whatever.
Having taken care of the live instruments that can be tuned, and the synths, you have few remaining concerns. Perhaps there’s a harmonica or xylophone that you mic. That’s going to be awkward, but I guess you could time warp the project to normal pitch for the overdub, then revert to normal (except for the overdub). Then pitch shift the overdub track down to 432.