Do I need upgraded power cables?

So great questions! I will start by saying “everything makes a difference or nothing makes a difference.”

The question for you is, it worth the money in the end? Again, already stated above, you will have to decide and make sure you have a return option.

So for me in my system the upgrade from the very same Panamax to a Audioquest Niagra 1200 was not subtle! you are correct the Panamax is basically surge protection, no noise filtering or suppression.  After that I proceeded to change out the power cable  to the Niagra, then to the amp. The next would be your digital power and or pre amp. A great way to do this is using the lending library at The Cable Company!  Call Steve, tell him what you have and pay to loan them out for two weeks. If you can’t tell any difference, return them and you had a nice forced listening session, if you did hear a difference you buy new or demo and apply your loan fee toward the purchase. A win win for very little money.

I will leave you with this, sea salt tastes different than mineral salt, and pink salt tastes different still!  They are all salt!

Audioquest’s thunder cable improved my sound. Use it on the integrated. Seems background more quiet, better dynamics. Idk, Maybe I’m imagining it. I also swear by cableworld’s Electra 7 on a preamp. Using audioquest’s Niagara 1200 pwr cond and Edison receptacle. A AQ z3 PC from Pwr cond to Edison, 20 amp dedicated. Do what you want, have fun.

If you are asking the question, the answer is no. 

There are times though (especially in dense musical passages) that the sound is stage is a blur - as if of all the instruments are coming from the same place.

A good power conditioner can sometimes help individual images pop by reducing noise.  Here’s an EQUI=CORE 1000 if still available you could probably get for $600 I’d think. 
https://www.usaudiomart.com/details/650092255-core-power-tech-equicore-1000/

Also, how are your speakers positioned relative to the back and side walls, how far apart, how much toe in?  Speaker positioning can also be a big factor in improving imaging and soundstage.

People knowledgeable about electricity will tell you a power cable is a power cable and won't make any difference. People that are members of the church of audiophilia will tell you the differences "aren't subtle" (a favourite).