Nah, the 10% refers to it using 10% of their base health.
The ~ indicates one is the minimum and the maximum value for the added flat health recovery bonus. Aka its slight randomized.
Meaning at worst a heal square only receives ((50 + (67 + INT)) × 1.5) × 1.1 as a static bonus.
Which should be 202 or 203 health for base 6 int depending on how it’s rounded down. or 853 with 400 int.
At best a heal square receives ((50 + (67 + INT)) × 1.5) × 1.3.
Which should be 239 or 240 extra health. Or 1008 for a 400 int build.
That should match both your tooltip heal descriptions.
