Xenoblade field graphics look jaggy/low-res

[Thad]

System:
Antergos
i3-7350K 4.20GHz
RX480

Relevant packages:
dolphin-emu-git 5.0r63 (AUR)
linux 4.15.3-2 ("core" repo)
mesa 17.3.3-2 ("extra" repo)
vulkan-radeon 17.3.3-2 ("extra" repo)

I've started playing Xenoblade Chronicles in Dolphin (using a save I copied from my Wii).  I've tried various graphics settings and HD texture packs.  Consistently, the graphics look jaggy and lo-res on the field, even though they look good on the start screen and the menu.  (Links go to screenshots, 2.3MB and 2.8MB.)

The issue has persisted across various different settings and texture packs, but here are the settings I had at the time I took the screenshots (and I realize these are probably overkill for my system and for a 1080p resolution, but I was trying settings and texture packs that are probably higher than what I need to see if they'd make any difference; I'll adjust for performance later):

XbC_Core_v8.4_2160p
XbC_Tutorials_Controller_r14_(PSX)

Backend: Vulkan
Internal Resolution: 4x Native
Anti-Aliasing: 8x MSAA
Anisotropic Filtering: 16x
Ubershaders: Hybrid
Post-Processing: Off
Force 24-Bit Color: On
Ignore Format Changes: On
Accuracy: Fast
GPU Texture Decoding: On
Store XFB Copies to Texture Only: On
Fast Depth Calculation: On
Disable Bounding Box: On
Load Custom Textures: On

Shouldn't these settings and textures be producing higher-quality graphics than what I'm seeing in that first screenshot?  What else should I check?  (I've tried FXAA; it looks maybe a little less jaggy but not much.)

Thanks.

[ExtremeDude2]

Do you have Scale EFB copies enabled?