This is referencing internal objects. The allocation and delay will get progressively worse with the more game objects you have in your scene. It also is looking for surface objects in order to cache some components.
For the next update I've removed all instances of this, so it should give better results. I've instead replaced each FindObjectsOfType() with a local library lookup instead, as well as implemented a Surface registration system so the module isn't constantly looking for water surfaces.
I can send you a preview of version 2.1.5 if you like, just send me an email. You'll need to replace the old Suimono Module prefab in your scene with the new one.
I'll be officially releasing it sometime in the next week or so.