From a Marantz MCR612 to a Yamaha A-S801 + WiiM Pro Plus — volume control and sub integration questions

A while ago I posted here asking for advice because I felt my previous setup — a Marantz MCR612 — was starting to bottleneck the rest of my system. After a lot of reading (including many recommendations from this sub), buying/selling gear and slowly upgrading piece by piece, this is where I’ve ended up:

Current setup:

Yamaha A-S801

WiiM Pro Plus

Q Acoustics 3050i

SVS SB-1000

Marantz TT5005

Main source is TIDAL through the WiiM via coaxial into the Yamaha DAC.

The difference coming from the MCR612 is honestly massive. The Yamaha feels way more effortless, more controlled and much more authoritative with the 3050i, especially in the low end and overall separation.

Current speaker setup:

Pure Direct enabled on the Yamaha

Rear ports on the 3050i plugged with the supplied foam inserts

Speakers about 20–30 cm from the back wall (can’t really move them further)

Roughly 2.5–3 m apart

Main listening position around the same distance

Couch/main seating slightly further back and closer to the rear wall

The thing I’m still unsure about is volume control.

I’ve tested both:

WiiM fixed output at 100% and volume controlled from the Yamaha

WiiM variable output and controlling most listening directly from the app

The WiiM/app control is obviously much more convenient for daily use, but I keep reading that fixed output into the amp is the “correct” way technically.

So my main questions are:

In a setup like this, is fixed output from the WiiM actually audibly better?

How are people here running their WiiM into integrated amps?

Am I overthinking this?

Any tips for integrating the SB-1000 with the 3050i without making the bass bloated?

At the moment I’m trying to use the sub more for extension/fill rather than huge bass output.