There’s another advantage of using 1.75mm filament – print speed. Heating less mass will always take less time, and if your goal is to print as fast as possible, you have two options ...

The trick lies in performing the join in a space only marginally wider than the filament width, in the case of 1.75 mm filament a short piece of 1.775 mm PTFE tube encased in a 3D printed clamp.