It doesn't appear to be a calcium issue, the plants are not showing any symptoms of such. I just checked out the latest Denver water report online. Most of the water is from snow melt streams, springs, and rivers feeding various reservoirs around the Denver area. In most cases water from sources such as this is very soft. The online report does not give water hardness or ppm of calcium or magnesium it does state that lime (CaO) is added to the drinking water so it is likely that most of the dGH you are reading is derived from calcium.
Your nitrates are a little low which could be causing the chlorosis you are seeing.
When I downloaded, enlarged, and enhanced your two pictures I saw some interveinal chlorosis on the older swordplant leaves with so necrosis along the leaf edges. In the second picture the newer anubias leaf on the left side of the photo is showing curling of the leaf margins, the leaves of the Ludwigia 'Red' are also showing curling, the leaves of the Bacopa are looking anemic - not as green as one would expect.
If it were my tank I would suspect an issue with insufficient magnesium (Mg). Here is the definition of a magnesium deficiency:
II. Symptoms do not appear first or most severely on youngest leaves: Effect general on whole plant or localized on older, lower leaves.
A . Chlorosis general, no interveinal chlorosis. Effects usually general on whole plant.
C. Interveinal chlorosis. Interveinal chlorosis first appears on oldest leaves.
1. Older leaves chlorotic, usually necrotic in late stages. Chlorosis along leaf margins extending between veins produces a "Christmas tree" pattern. Veins normal green. Leaf margins may curl downward or upward with puckering effect. Necrosis may suddenly occur between veins. Potassium or calcium excess can inhibit uptake of magnesium...magnesium deficiency
When the external magnesium supply is deficient, interveinal chlorosis of the older leaves is the first symptom because as the magnesium of the chlorophyll is remobilized, the mesophyll cells next to the vascular bundles retain chlorophyll for longer periods than do the parenchyma cells between them. Leaves lose green color at tips and between veins followed by chlorosis or development of brilliant colors, starting with lower leaves and proceeding upwards. The chlorosis/brilliant colors (unmasking of other leaf pigments due to the lack of chlorophyll) may start at the leaf margins or tips and progress inward interveinally producing a "Christmas" tree pattern. Leaves are abnormally thin, stems are brittle and side stems have a tendency to curve upward. Stems are weak, subject to fungus infection, usually leaves drop prematurely.
Here is what I suggest:
Increase your Thive dosing so nitrogen (NO3) the 20 ppm - 30 ppm range per your test kit.
Continue dosing Seachem Flourish Iron per instructions on label 3X per week
Add Epsom Salt (magnesium sulfate / MgSO4*7H2O) to your dosing routine. Do an initial dose of 1/2 teaspoon per 10 gallons. Thereafter, add 1/2 teaspoon per 10 gallons of new water added during water changes. This should increase the magnesium in your tank by about 5 ppm and the dGH should increase by about 1 degree.
Now the hard part, waiting. After you start the change in dosing you should start to see some changes in the new leaves as they emerge; the existing leaves will not change.
The new leaves should look greener and healthier (and possibly larger). As the newly emerged leaves mature you should not see the interveinal chlorosis and leaf margin curling that we see now in the Amazon swordplants and the Ludwigia 'Red'.
Post pictures as things progress, let us know how things are improving (or not). It helps others when the results are posted. -Roy