You are correct. Nearly $1B sunk into SO4 and KLL combined and...

You are correct. Nearly $1B sunk into SO4 and KLL combined and only 1400T of SOP to show for it.
The latest production costs from KLL are grossly higher than their feasibility.
The SOP pricing being promoted by KLL and APC in their attempts to raise cash is significantly higher than the mid term projections both were recently using. Hoping for prolonged elevated pricing, the result of the Belarusian/Ukraine/Russian situation, on the back of a strong US dollar is wishful thinking.
KLL has a significant borefield operation with flotation based processing and a trucking operation. How much different to this is what APC is proposing? MOP conversion is an obvious difference, the initial scale is larger and they will have renewables. APC will be doing very well if they can keep costs close to feasibility.
The two substantially larger projects further from development do have some points of difference as well as increased scale. Their economics may well be better but this is far from certain and given the mess made by SO4 and KLL, all projects yet to start face funding hurdles.