Thought I had mentioned it in the comment but apparently not, must have been thinking of the video.
Those temperatures are off of a probe on the back of the enclosure, right next to the solid state relay. I have it heatsunk with some MX-2 thermal compound to the back, so it's effectively the temp that the rear of the SSR is going to be at. The 2w per amp estimate is pretty useful though, had I thought of this in advance I would have probably designed it a little different but I do feel optimistic about the solution I hopefully found. Fans should be here tomorrow I think, and I have the shroud printing right now, though I'll have to check clearances in the actual box, since it's not 100% accurate to my cad setup.
There are cutouts for ventilation on the sides, so it's not sealed, but at 70 watts from the SSR, convection cooling isn't going to be enough for sure, though you can definitely feel some airflow out the vents when it was at the high end.
at .12 ish cubic feet for the enclosure, not taking into account the stuff in it, and assuming I get the full spec out of the fans which I won't because of resistance in the duct and whatnot, I'd be able to pass the entire volume of the box through the heatsink 230+ times per minute. Pretty sure I'll be able to dial the speed down a fair bit lol