Yes look for leaks, both on the exhaust and the compressed air side. I didn't properly retighten the intake hat to the intake manifold and it cut my boost in half. You could hear the leak, though, a kind of an extra roar. Didn't sound right and I went right back home
Intake restriction (air filter) or exhaust restriction can also cause a low boost situation.
Was this a new or used kit installed? Just wanting to make sure the correct turbo is installed. IIRC, the Hypermax is unusual in it's plumbing and while I can't advise you on them in specific ways, it's probably worth looking at the install instructions and make sure it's all properly plumbed.
Also, verify from a good source what sorts of boost levels you SHOULD be seeing from a Hypermax kit. Not somebody internet WAG but either from Hypermax documents, Hypermax or someone who runs a system like yours.
It sounds to me like the smoke is a product of not enough air, i.e. you set the pump up for a turbo that is designed to push a specific amount of air. If that turbo isn't working as designed, you get smoke. Setting the fuel back might lessen the symptom but it isn't the problem itself. I guess if you can't get to the bottom of the air problem, the short term solution is to turn the pump back.