UHD 630: some animations are stuttering. low performance overall

Hello lovely people 😊

I am having issue with my Vanilla Mojave 10.14.6 (18G87) freshly installed with freshly made config.

The issues are: some of the animations are stuttering like opening Launchpad, making selection on desktop the rectangle stutters, moving windows etc. is delayed a bit or stuttering. Very rarely I have my iGPU working smoothly.

My configuration:

Motherboard: MSI B360M Bazooka (MS-7B24)

CPU: i5-8400

iGPU: UHD 630

RAM: 2x8GB 2666Mhz

SMBios: iMac18,1

SSD: Crucial MX500

Some wifi and bt

Drivers I have installed on my Clover (5037 or newer):

ApfsDriverLoader.efi

AptioMemoryFix.efi

EmuVariableUefi.efi (needed on my board for NvRam)

HFSPlus.efi

Kexts I have installed (I updated them recently to latest):

AirportBrcmFixup.kext

AppleALC.kext

Lilu.kext

RealtekRTL8111.kext

SMCProcessor.kext

SMCSuperIO.kext

USBInjectAll.kext

VirtualSMC.kext

WhateverGreen.kext

My config: https://pastebin.com/AWvuJsYq

Yes, I have been faking my iGPU with device-id and ig-platform-id as Kaby Lake (it was just easier for me tu run when using High Sierra with my GTX 1060 + quick sync (iGPU) because it was showing there as Kaby Lake. But that faking shouldn't have any impact on that iGPU performance, right?

Do you have any ideas what to check, what to change?