That's a clever one I hadn't thought of. I use ascii character codes for a few symbols that pop up from time to time, but it didn't occur to me to use it to force a lower-case E whenever "we" is typed.
Unfortunately, copying and pasting your unicode numbers into Instant Text did not stop "WE" from showing up as "WE". At first I thought it might be that Microsoft Word overruling/reinterpreting the keyboard command after the fact, but it does not "minisculize" the E even in notepad.
On trying your "{lowercase}" solution from the other comment, it also does not work. There, I think the problem is more evident: I can see the selection/replacement "flash" happening ONLY on "we" but not on "WE" (or even "We" for that matter). This was the same as the unicode command, where I saw the split-second replacement on "we" but nothing for "WE" or "We". My layman's guess is that it seems that the capital-W is being treated differently than the lower-case W by Instant Text... at least for me.
(For clarity's sake, I copy-pasted the text directly from your reply into the entry window. I assume this is not a factor, but figured I should mention it.)