In Florida it has been mentioned many times that "Turpentine" is the preferred rootstock.
In my continued research ( I often have a lot of time on hand ) into rootstock, and trials done on them. I have come up with this information.
Gomera-1 is suspected of being turpentine. ( further research has shown they are not the same )
Mangoes grafted on Gomera-1 are a bit more cold hardy, and can tolerate winds better, they will produce more fruit , but the fruit will have less weight compared to Gomera-3. Gomera-1 is also has shown better salt tolerance.
Gomera-3, has the advantage of producing bigger trees, and larger fruit.
In other research, Olour and Muvandan have showed best results for Alphonso in terms of production and salt tolerance.
Vellaikolamban rootstock is dwarfing and recommended for high density planting. ( Something i was looking for ).
I am also a believer in using beneficial fungi etc on plants. so I also went looking for information on beneficial strains.
Gigaspora margarita is what you want to sprinkle on your roots or mango seeds, which will give you higher graft success and more productive trees, inoculating your rootstocks with G. margarita will cut the time needed before you can start grafting on them.
Anyway i am just throwing this information out there, in the hopes it may be its useful to someone