For fertilizer, in the spring, i just remove a bit of the top soil, add in with new soil a palm plant mix. Cover with mulch to aid in water retention. During the summer months, about twice a month, i'll use a very diluted fish fertilizer mix 5-1-1 and i'll add in soil acidifier and other micro nutrients. It's all heavily diluted. Basically whatever is appropriate for 5 gallon mix, it will be used as a 10 gallon mixture.
I feel less of the nutrients but fed more often is better since its all in containers. I don't want to run the risk of fertilizer burn.
I also have sabara in 7 gallon container, it fruits but poorly unlike the one in the pics. The sabara trunk and height is much bigger, so I was expecting tons of flowers but it still seems to prefer to flower lighlty on the ends of the branches instead of the trunk. Still working on it.
I would suggest having a different variety of Jaboticaba as a backup. For me, space is a premium so I went with a 4 way grafted plant. That way, one plant can keep me busy with 4 different varieties of fruit and I only have to haul back one plant during the winter.
The grafted one I'ved had for several years now, I've gotten fruit from it the last 4 years so not too bad.