The majority of people who use Deca don’t use caber (you can also use Pramipexole of Bromocriptine) and are fine, but it’s a risky business. High prolactin is no joke and it can take MONTHS to recover from! Not trying to scare you or anything, just making you aware of potential risks.
A fairly easy way to get a good cycle for yourself would just be to increase your test from 500/wk to 750/wk and add some dbol for the first 4 weeks.
It’s not the compound that decides whether or not you keep your gains, it’s your diet, training and PCT. Some drugs, like dbol for example, can make you hold more water than others so you might gain more scale weight which you’ll lose when you come off, but that’s not muscle you’re losing.
Think of it like this: Person A does a cycle with “wet” compounds like Deca and Dbol, gains 20lbs and loses 10lbs during PCT. In his mind, he’s lost 10lbs so the gains weren’t keepable. Person B uses “dry” compounds like Tren or something, gains 12lbs and loses 2lbs in PCT. They’ve both gained 10lbs, which is a solid gain, but their perspectives are totally different.
Long story short - I reckon you’d be happy with the results of a 12 week cycle of 750mg test, with 40mg dbol every day for the first 4 weeks.