Do I need a new DAC/streamer. Considering?

You could absolutely add just a server/renderer. I was shocked when I added a Nucleus+ to mine. Made more of a difference than moving from a Marantz Reference DAC to PS Audio DSD.  Server is way more important than you would think.  

When I added it, I was running a PS Audio BHK Pre, PS Audio DSD and VTL MB 185s....not a small investment either.
I have since done a lot of investigating and the weak link in the chain is the Server. Antipodes explains this pretty well. The internet is volatile and needs something powerful and stable as data comes in. The renderer actually requires less power.
This has a huge impact on sound quality. I was very confused when I added my server and it improved sound noticeably.
The best possible solution it to separate the sever, renderer/player and DAC. This is more because the server is better if it doesn’t have to deal with the secondary load of renderer as well.

The DAC in the C53 is pretty good.  You will probably need to spend quite a bit to outperform it.  
The Bluesound Node is a decent entry level streamer but is not in the same league as your other gear.  You would benefit from adding good server and renderer.  Either separate or combined.  
Lots of options.  Auralic and Lumin are good choices.  So is just using a Roon Nucleus or an Antipodes S40.  This avoids DAC redundancy but does require...Roon in the case of the Nucleus or some 3rd party software for Antipode.

There is definitely no need for a DAC in the streaming device and the only question is whether you want a server between your streaming service and your player or you want to go straight to the player.  Streamers bypass the server and you are simply directing Tidal or Qobuz to your player.  This exposes your player to the volatility of the internet. 

If you have a server in place between player and streaming source (Tidal Qobuz) you get a more stable signal as the server brings in the track and then delivers it to the player. 

If you run Tidal or Qobuz through Roon, it undeniably sounds different than if you send it straight to your device.  I have recently tested this with Tidal through Roon to my 2Go/Hugo 2 vs sending the signal straight to the 2Go through Tidal.  I have a Roon Nucleus+ on my network.  The sound is a bit thinner in the midrange and airier in the treble when you go straight to the 2Go.  Far from ideal.  I found it quite different and found the 2Go was inferior when dealing with Tidal directly vs the Roon Nucleus+ handling it first.  I have no DSPs running in Roon.