First if its smoking at the negative terminal that almost sounds like a battery issue.
even though the terminals are not well done I don't see how it would cause smoke.
unless your blowing vapor back
thru.
I admit mine is not working how I wish atleast as of yet.
It slowly getting better but still have my issues with it.
& carlos asks me randomly how its going & says he wants to make it right.
He has showed me a few units & how good they work. Showed me some of the parts & stages. So I understand why it takes a while.
Also each of our units will be different due to handmade & its hard to make perfectly identical units by hand. could be 1/32 or more difference & hard to perfect by hand & multiple people to upgrade & test each unit.
Just my personal opinion though.
I still think carlos is a good guy & doing great. Just needs some improvements & knowledgeable help.