i have seen your other post last year about this topic, but haven't seen a solution for the following problem. All my websites with buttonizer add 1-2 sec loading time in GTmetrix and that is not good. When i disable the plugin the site loads faster for 1-2 seconds according to GTmetrix.
Here is a report https://gtmetrix.com/reports/velomakerke.be/3kVZvr1B
When you look at the waterfall your plugin adds 1.32 sec.
I use WProcket to speed up my sites and most websites gives me 1-1,5 sec or below 1 sec loading time. But with your plugin it gives me 2-3 seconds loading time with GTmetrix.
Have you got an solution for this issue?