Solved!

First of all, I learned from other forum topics that I was using the wrong settings. I am now using the following:

3 = 0 (turn off the delta function)

101 = 770 (report watts for clamps 1&2 and multi sensor watts (total watts))

103 = 6152 (report kWh for clamps 1&2 and total kWh)

111 = 10 (report at 10 second interval for the watts data in 101)

113 = 60 (report at 60 second interval for the kWh data in 103)

Then I set variable 1 back to 120. Sure enough, Watts spiked back up to over 400k per clamp, and at one point over 1 million for the total.

Then I added variable 255 (reset HEM to default configuration), 4 byte dec, value "0". I had to configure the node twice, and it always returned an error. But low and behold, the watts magically started showing reasonable figures. After 24 hours, I am now confident that my power data is reading/reporting properly.

Other notes:

Variable 255 is a reset to factory default configuration (not a recalibration of the HEM), but it did not wipe out my other configurations in 101-103. Once the meter was reading properly, I deleted variable 255.