First thing you have to do to change the Clerk Live-Search, after the first data sync has run successfully, is to go into your Magento2 backend, click on STORES and then CONFIGURATION:
Next, scroll down and find the tap named CLERK, click and press CONFIGURATION:
Click on the tap LIVE SEARCH SETTINGS, choose your preferred settings in the four fields and finish by pressing SAVE CONFIG:
The changes take effect immediately.