Missing Plugin Icon in the Toolbar Editor [sketchup 2016]

[lianproiemti]

So, I was having a trouble with organizing my icons on the toolbar editor.
I wasn't able to add some of the icons on my customized toolbars because it doesn't appear on the search bar.
I was using a Sketchup Pro v2016 and installed a plugin called "Split Tools" by

TIG

. Though it can be toggled in the View>Toolbars and it is working just fine, two of the three icons (SplitDonut and SplitUp) does not appear in the search bar of the toolbar editor.