For years on my windows systems, I've used a tool called TouchCursor (https://martin-stone.github.io/touchcursor/). In brief, this lets you pick an activation key (by default SpaceBar) then remap other keys on your keyboard.
For example, SpaceBar plus the letter I instead triggers a Cursor Up movement. SpaceBar+K triggers Cursor Down. Similarly, SpaceBar+J and SpaceBar+L are cursor left and right.
This is great as it lets me move the cursor around in my current document, or scroll web pages up and down without taking my keys off the "home row" position of the keyboard. You wouldn't believe how much faster you can type using this.
I've tried to emulate this using BTT, but with limited success. The problem with BTT is that it still lets the keystrokes through, then uses either CTRL+Z or two backspaces to remove the characters.
While visually distracting, it's not horrible in a text document. However, in other places, it can have unintended consequences.
Is there a way in BTT I can tell it not to let the keystrokes through, and instead just replace them with the replacement key? I.E. don't let SpaceBar+I in and replace it with a Cursor Up? I tried but couldn't figure out a way.
If not, does anyone know of a tool that might be able to do this?
I will add I've been a Better Snap Tool user for quite some time, and it is on my short list of indispensable Mac apps.