I think I found a glitch in your area for Form 8962, Premium Tax Credit if I'm receiving an ACA subsidy, where you omitted one of the income cliffs. It does a nice job showing the subsidy repayment limits and amount owed if I end up with higher than estimated income, but if I go over the 400% FPL by any amount, the repayment amount on your worksheet goes to zero, whereas I believe I should then be obligated to repay the entire amount of the subsidy received, which should greatly increase my total tax owed.
I'm trying to do an optimization looking at the balance between my ACA subsidy received, and long term capital gains received within the 0% rate. Obviously, 0% on LTCG is good, but a big chunk of the LTCG could be wiped out if that gain pushes me over the ACA subsidy cliff. Knowing my net earned income, it would be nice to be able to increment my LTCG and see the increasing hits I'd take on ACA subsidy repayment, to best plan what to sell in a year and pay the lowest overall tax rate.