Stromberg90
Feature similar to Mayas middle mouse target weld option
Could it be possible to add a feature to weld vertices to the center without having to manually change the location? Like mayas middle click or a shift/ctrl.
In case you haven't yet realized, you can already do a Shift+LMB or Ctrl+LMB by adding a second keybind in the keymap and changing the merge location to Center. Note: This will NOT work for middle mouse in the current version of the add-on because it specifically only looks for LMB events.
I'd like to be able to support MMB but I would also like to maintain compatibility with both the default Blender keymap and the Industry Compatible keymap and therein lies a problem: The default Blender keymap has MMB assigned to Rotate View.
One possibility is to try reading which keymap the user has active at the time the addon is installed and then automatically use a different merge-at-center keybind for the tool depending on that result, such as MMB for users of the Industry Compatible keymap and Ctrl+LMB for the Blender keymap. This would introduce an inconsistency but it might be worth it (assuming this property is allowed to be read during install).
However another issue is that Ctrl or Shift + LMB would block the pass through of extending selection while using the Merge Tool, i.e. if you wanted to select multiple vertices to do a multi-merge without having to leave the tool. I don't know how often people use it that way. If the main use case is one vertex at a time (this isn't relevant in edge mode) for 99% of all operations then it might be worth blocking that passthrough.