I think i may recognise the issue here -as i am about to face a similar or related issue myself…:
the FoV in the camera used to get the target on the slit/fibre hole in the spectrograph set up and then guide on it can be pretty small (the FoV is narrow so that the fibre hole/ slit is more prominent ). This can be fine for guiding (even then it can be tricky if no suitable stars are in the FoV and the target star itself has fallen into the hole/slit…), but it is not good for pointing…so in some cases we might be looking at a camera to collect the spectra themselves, a camera looking at the fibre hole/slit and a third camera to do the pointing.
As Leonardo says the use of a multi port hub like perseus allows pointing with one port/camera to get the target very close to the spectral acquisition slit and then switch ports if there is some benefit there depending on the setup, but likely does not itself solve your issue.
the most straightforward approach would likely be to precise point using a wider field of view camera then use the new offset RA/DEC commands in voyager to take care of the fibre hole not being at the centre pixel of the image (likely plus a little bit of manual jogging onto the slit)…and then continue to use that camera to guide - but that will rely on the camera being able to attach to both Phd (or other guiding software) and as the main imager for voyager for the pointing bit…
Leonardo as systems integrator will have a view on whether that is possible in theory depending on the camera - or possibly the use of a software “hub” (Optec have an ascom hub specifically for this purpose but I have not tried it with 2 clients accessing a camera…Optec :: ASCOM Server Download)…I wonder if this can help…?
On thing that certainly would help with multi instrument setups would be the ability in scripting to specify the PHD profile (external control of choice of multiple profiles I believe are a more recent ability within PHD ).