As long as he can keep the temps the condenser is in below 100F (preferably below 90) he should be ok, but energy wise the unit will work harder to condense refrigerant and of course venting the heat with a secondary blower will use added power.
I have seen so many units installed this way burn up in a year or two so hopefully that doesn't become an issue. Definitely not ideal but when stealth is required you gotta do what you gotta do.
If I get this air flow thing set up right, I will be able to keep it below 90/100... That is my goal. And you are absolutely correct, I gotta do what I gotta do.. Honestly, I don't care a bit to invest in a new minisplit every year or other year, if I have to. I know some may think it's crazy but it pays off...
So if I have this set up, to where I am pulling air through the unit, same temperature as it is outside, how will I be damaging the unit other than maybe making the blower fan on the unit work harder by adding a secondary fan?