Is it better to do my visa extension in Phuket or Bangkok?

Hi peps.

So my last post was about me got pulled aside at Suvarnabhumis Airport from Laos, all went well after all, i'm glad.

So now i have another question regarding my extension. I have a planed trip to Phuket 25-26th of nov and i'm thinking to just do my extension there instead of in bkk.

Is that wise or should i just stick with bkk? The last day for me to do my extension is 15th of dec. Is it better to wait until the last few days or can you just go to immigration as soon as you leave the plane? And again is immigration in bkk "easier" compare to Phuket?

Thanks in advance :)