Remember to disable IconBeFast functionality as icon.library present in BB3 comes with that built-in.
Sorry, but that's wrong since IconBeFast in SystemPatch 3.x is version 1.16 and patches the graphics.library function ObtainBestPenA() which is used by many graphic tools too (picture viewers etc). And the optimized code of the icon.library 46.4 uses IconBeFast v2 and many additional speedups, but only for icons, of course. Thus, you can use both at the same time. ObtainBestPenA() can still help to accelerate loading a collection of thumbnail images for example.
Just as background information:
The original icon.library of the AmigaOS makes up to 512 calls to graphics.library ObtainBestPenA() for the color mapping of each icon together with 512 OtainSemaphore()/ReleaseSemaphore() pairs etc. So, IconBeFast v2 avoids all these external library calls by including a copy of the OptainBestPenA() functionality directly into the icon.library which subsequently also makes a lot of further optimization possible.
But, if you use SystemPatch v2.x or v3.x then please remove TagLiFE from your startup-sequence, because that's also included in SystemPatch already.