I think he'll eventually play all 3 formats. He's even showing signs of adapting in PSL and domestic T20 where he has increasingly good averages even though it shouldn't be his forte. If he can adapt to that, adapting to tests should be even easier to him as it suits his style of play more.
In Imam's first 4 tests, he averaged 43.50. He fell away in the next few tests. But 11 tests really isn't a big enough sample size. Given his age, the fact he's regularly playing international cricket so will be exposed to high level competition and access to the best coaching and facilities in Pakistan, he has far more room for improvement.
There's no need to rush him in tests necessarily, but it's going to happen sooner than later. Perhaps best to wait until he starts raining in the runs in first class. Which again is only a matter of time, I'm sure it's harder to open in ODIs and average 50 at a SR 80 than it is to score in first class domestic, regardless of whether Imam's a selfish player or not. Selfish or not, he's shown ability to grind out an innings in international cricket, which is something most of our players struggle to do.
He hardly will play first class becouse they will be same time as the international games.i think he can be tried in tests but i hsve seen a weekenes in playing the short ball and fishing outside of stump.he defonitely shouldnt be playing t20s.