[dice]

Grafting with eggplants has variable results. One paper I read
studied grafts with an eggplant cultivar and a disease-tolerant
tomato cultivar for roots and two different tomato cultivars
for the scions. With one tomato cultivar, they got more
production from the eggplant graft than from either the
tomato-tomato graft or the ungrafted plant of the scion.
With the other tomato scion they got less production
from the eggplant graft than from the ungrafted plant.

So no guarantee, but if the problems are typically root knot
nematodes or bacterial wilt, it is worth a try with your favorite
heirloom tomato, since those are two problems that eggplants
in Asia seem to be immune to.

You might be able to find some fast growing F1 tomato
with the necessary disease tolerance (that you normally
would not bother with due to lack of flavor) to try, too.

Edit:
The tomato cultivars that they used in the study just had numbers
rather than names. I got the impression that they were commercial
cultivars supplied in bulk by some seed company to farmers in Taiwan
and elsewhere around Asia.