There will always be a huge variance in blackjack with or without a calculator. It's just an indication of the odds are in your favour or against you, in the end you can still hit a bad streak and just be unlucky.
I think we need someone to try this for a few weeks and see how it actually turns out. Just using it in a few hands seems not enough to me.
If there's someone who can do that and show the outcome both win or lose without
any changes of the results.
It will be a good basis if this calculator really helps or not,
and yes the chances of hitting the long streaks is always possible
it's unavoidable if you continuously playing without any discipline.