Next step in improving digital chain?

I'm looking for suggestions on the next logical step to try to improve my digital chain in.  I know I've got a few opportunities, but there are multiple ways to begin and looking for advice.

Today:  Ethernet -> Intel NUC running Roon -> USB Cable (Audioquest Forest) -> iFi iPurifier 3.0 filter -> Border Patrol DAC (and from there via Chord Shawline RCA -> DIN to SuperNait 2)

I could audibly discern a difference adding the iFi Purifier, as well as when I upgraded from a generic USB cable to the Audioquest, but I know neither are the be-all, and also that the Intel NUC isn't the final word in USB sources :)

1. Take the Intel NUC out of streaming and go with a lightweight streamer/Roon end point such as microRendu + LPS?
2. Keep the Intel NUC, but investigate something more heavy to improve the USB coming out, such as the UpTone USB Regen and a LPS?
3. Keep it simpler and just upgrade the USB cable
4. Add a LPS to the Intel NUC so it's a less noisy streaming source (but not sure how much inherent noise in just the PC design itself)
5. None of above, try something different...

Anyway, it's one of the rare instances where the number of choices available has me a bit stumped on next step to try.

PC’s are fing noisy, are you using a optical cable from the PC? This will be the best for electrical isolation, after that you can connect anything and it should be noise free all the way down the line. I have used a Optical cable from PC to a Monarchy DIP then out via digital XLR to a external DAC then to a active preamp via rca's then rca's out to a Headphone amp which drives phones or a Bose 2.0 computer audio system.

I didn't think the Intel NUC had an optical out, but your question had me google it, and there may be a minijack/optical out after all.  But then there's a next challenge... my Border Patrol DAC is USB-in only.  So then I'd need to convert signal to USB (I checked out the Monarchy DIP, and if I'd have sprung for the Border Patrol to have USB + SPDIF output, that would have worked).

At that point, saying 'to heck with it' and just getting a lightweight streamer to connect via ethernet to the network seems potentially simpler.

The iPurifier 3.0 has a done decent job improving the USB out from the NUC, but I'm not really sure how much headroom for improvement of further USB cleanup there is.  

I suppose one thing I *could* try though is bring the Auralic Aries w/ LPS down from the main system, and compare the USB-out on that vs. the NUC+iPurifier... and if that trounces the current setup, I'll have proven it's worth doing further improvements.
ROCK 1.0 (Build 183)

Looking at Roon forums for a few minutes, I can't seem to find folks who are using the mini toslink output.  But if they are, it doesn't get around my need to convert to USB.
I would think in terms of bang for the buck an LPS for the NUC would be the way to go.  Barring that perhaps replace it with a better streamer so option 1. However if you like the sound you're getting now the LPS should really improve it.
I have a fanless NUC running ROCK and use a raspberry pi4 as an endpoint with USB into DAC.  I have also used the NUC straight into DAC with USB and never had a noise problem. If you are noticing a lot of noise it's probably the DAC more than the NUC. Border Patrol doesn't measure to well in jitter noise rejection so no matter what you put in front of the DAC you will still  get the same out of it.
Thanks, the LPS into the NUC is an interesting idea, and something I hadn't really considered.  

And honestly, I don't really have complaints about the NUC -> Border Patrol setup, I was more curious if there were 'more veils to be lifted'.

As a very happy Border Patrol owner, I'm super familiar with those Stereophile measurements. I'm *also* a Benchmark DAC owner, and I've spent a year with both DACs in the system (going back and forth), and honestly, I just like how the Border Patrol sounds better. 

What's wrong with some sweet lies, when enjoyment, not scientific measurement, is the end goal :)
@kishekar let your ears guide you.  Borrow or home-try some of the options, and choose what sounds best to you. Have someone blind swap components and if you can't discern a difference; keep your $$$. 

My point was I'm not sure what " veil" could be lifted that you would find audible considering the inherent properties of the Border Patrol DAC. Some like the sound of R2R DACs nothing wrong with that. I assumed you had a noise problem if not I doubt changing power supplies will do anything since the point of switching them out is to reduce noise. 
As is indicated by the Stereophile review, any noise introduced on the USB bus will result in timing errors on the DAC since this DAC is particularly sensitive to jitter.

If the OP is happy with the sound from this DAC, then the best strategy would be to take steps to reduce noise and jitter on the digital connection to the DAC. Adding an LPS to the NUC will likely help, but more improvement might be realized by using a USB reclocker or streamer that is optimized to achieve the highest quality digital connection. 

The OP already mentioned the Uptone USB regen and the MicroRendu. Another option to consider would be one of the newly introduced Denafrips digital-to-digital converters. Since these are brand new, there are no reviews yet, but based on the high praise that Denafrips has received for their DACs, these will probably be an excellent value.