it depends if the reflux is caused by or exacerbated by MSPI.
go to page 2, here, for the best explanation about allergies/intolerances:
if baby does not have any intolerance or allergy issues then a regular formula should be fine. I breastfed my silent refluxer and, for him, I figured out it was not MSPI bcse I essentially made my milk to be like an elemental formula and there was no difference in symptoms, stools, etc, with my milk being like an elemental formula or after I went back to having my milk be like a ‘regular’ formula…