texture cutting

Hi there.
As shown below, in architecture, perforated plate material as shown below is frequently used.

253651-6.png

In many occasions, hole size needs to be adjusted. If I amend texture in external program and then import into UE4, it is very inconvenient and not intuitive. So that I hope to solve this issue by cutting texture in UE4. But I failed to find such function, then I wrote material by myself as shown below.

253652-7.png

Through above mentioned function, texture is cut by 30%, although it solves above mentioned issue, but new issues emerge: joints shown on connecting places of texture. I guess it caused by precision of Frac nodes. But I have not found out any solution yet. And issues would occur if such network is connected to socket in customized UV.

253653-8.png

Is there any better solution for such issue?

… having same issue here, did you find any solution thou?..