> Sadly, solutions like BetterTouchTool and InstantSpaceSwitcher won't work for me because I prefer to use my trackpad to switch spaces.

One of BetterTouchTool's first features ~17 years ago was trackpad gesture customization, it is still one of the most important things you can do with BTT! ;-) You'd just need to assign the "Move Right a Space (without animation)" and "Move Left a Space (without animation)" actions to trackpad gestures in BTT.