BillDH2k

Here is my working EFI OC097 for Latitude 5490 (i5-8350U, Intel Wifi), for Sonoma. Due to file uploading size limitation, AirportItlwm.kext (V1.23 Alpha for Sonoma) is not included. Both HDMI port and Display Port via USB-C port are working.  You may give it a try. 
 
This EFI was based on this GitHub repository: juanpy0223/Dell-Latitude-5490-8th-gen.
 
My bios is still 1.26 and did not update to the latest (V1.32) since the latest BIOS may prevent the CFG LOCK changing. Also once updated, it can not go back to earlier BIOS. I experienced this with my Latitude 5400.
 
If you are able to disable CFG LOCK with 1.32 BIOS and set DVMT to 64MB (instruction is in the link above), then you can make the following changes to the Config.plist:
   - Root->Kernel->AppleCpuPmCfgLock  = FALSE (for native CPU power management)
   - Remove the following two properties from your iGPU's DeviceProperties (PciRoot(0x0)/Pci(0x2,0x0) for my case):
         framebuffer-fbmem
         framebuffer-stolenmem
 
Goodluck!
DELL-5490-OC097.zip

@Baio77  It turned out to be a simple fix. The culpit was that GPIO device in the unit #2 was not enabled by the generic "SSDT-GPI0.aml" patch used in my EFI. I had to use a different method, by setting GPEN =1, to enable it (as explained in the OpenCore guide, for my particular case). Also, I updated to the latest woodooI2C.kext. Now the touchpad worked!
 
Here is the updated SSDT-GPIO.aml, only works on unit #2 (it's BIOS ACPI code will enable GPIO if GPEN =1):
/* SSDT-GPIO.aml */ DefinitionBlock ("", "SSDT", 2, "DRTNIA", "GPI0", 0x00000000) {     External (GPEN, FieldUnitObj)     If (_OSI ("Darwin"))     {         \GPEN = One     } }
For comparison, here is the generic patch, which works on unit #1, not unit #2 (#1's BIOS is different. Not 100% sure caused by the version difference, or hardware difference):
DefinitionBlock ("", "SSDT", 2, "hack", "GPI0", 0x00000000) {     External (_SB_.PCI0.GPI0, DeviceObj)     Scope (_SB.PCI0.GPI0)     {         Method (_STA, 0, NotSerialized)  // _STA: Status         {             Return (0x0F)         }     } }  
@Baio77: The AlpsHID kext also worked, but GPIO must be enabled first.

1. Download the appropriate version from the Releases and extract the zip file.
Let’s assume that you downloaded “ALCPlugFix-Swift-RELEASE-1.5.zip” to download folder, and extracted the zip file in the same place (by double-clicking). You would have a new folder “ALCPlugFix-Swift-RELEASE-1.5” created. Right-Mouse-Click on the new folder icon -> Services -> New Terminal at Folder.  A new terminal window would be opened at the current folder path: /Users/YOURNAME/Downloads/ALCPlugFix-Swift-RELEASE-1.5  (You can type “pwd” to verify it)
 
2. Copy the edited sample.plist file (in this case: ALC295-DELL7400.plist) to somewhere safe.
I placed it in “Monterey HD\users\shared”, where Monterey HD is the name for my macOS drive. You may have a different name.
 
3. At the terminal (opened in step 1), type: ./install.sh
Follow the instruction. When it asked for .plist file, drag “ALC295-DELL7400.plist” icon to the terminal, from the location you stored in step 2 above (in my case, it is from “Monterey HD\users\shared\”).
 
You may encounter message like "ALCPlugFix is from unknown source” (1st time install) , just ignore it. After install is completed, go to folder: /usr/local/bin  (this is where ALCPlugFix is installed).  Right-Mouse-Click on ALCPlugFix icon -> Open, then Open again to allow it to run. This would give it the permission to run.
 
Add "alcverbs=1 alcid=77" to the boot args.  Reboot.