Should have no negative impact. The reason to use XLR to TRS is because that preserves the balanced nature of the cabling. You can also go XLR to RCA and that would likely work fine also, but there's no advantage to doing so. XLR/TRS is used for balanced cables, which is used in the professional world as it prevents noise on long cable runs as are common there. For home setups it's generally unnecessary and RCA (unbalanced) works fine for the short cable lenghts there. But again, there's no disadvantage either, except that balanced cables and connections are generally a bit bulkier and more expensive.
The LP6-v2 would work the same way, except that the individual right left/right speakers have their own input rather than having all the inputs on one speaker and then a cable that connects the primary speaker to the secondary. So the diagram would change to this:
View attachment 418220
You'd still need a subwoofer with inputs, outputs, and a built-in crossover function like the WS 6.2 (though that's hardly the only subwoofer with those features). You could also just go straight XLR with those, rather than XLR to TRS, as unlike the UNF the speakers have XLR inputs.
Honestly, the simplest setup that would enable you to use most any subwoofer wouldn't be going the active monitor route. I might suggest considering the
Wiim Amp, which is a combination streamer, DAC, and amplifier. Then you can hook up any passive speakers you like using standard speaker cable. It also has a subwoofer out, an RCA port which you would connect to the corresponding RCA input that pretty much any subwoofer on the market has. The Wiim Amp can handle the bass management through the Wiim app which is pretty straightward. For starters, you would probably just want to set an 80Hz crossover.
Then, as you get more comfortable, you could start experimenting with more advanced stuff that the Wiim has to offer, such as equalization and room correction. If you want. Or you could just get it working and enjoy it.