Plugin I threw together due to the built-in welder seemingly losing the functionality.
This plugin allows you to quickly weld all selected parts together with a single click - treating the first selected part as the origin for all of the created welds.
You can also set a shortcut to make this process quicker without needing to click the Plugin’s button in the file menu under Advanced → Customize Shortcuts.
Link: https://create.roblox.com/store/asset/97771311818408/Welder