Clone Array Very Slow

I have a image 10px by 10px all black and I wanted to clone it to the max 99 and the operation is exceptionaly SLOW. Krita was marked as non responsive on the system for the long while.

I think I would do this operation by hand faster than I was waiting.

Is there some way to make it a tad faster and not about to crash Krita in the process?

I am on the Windows version with 4.4.1

Not to mention if there is operations that take so long present the percentual progress having an expected time to finish would be good to evaluate if this operation is worth the time spent on it or should I just do it another way.