I am going to put this here as I think it could help save someone some time in future (would have saved me ages, just found one random few word comment on Reddit somewhere that helped me)

Just spent many hours getting my PS4 wireless controller to work properly with Nasomi ffxi and DS4windows, this wont deal with any in game controller lag etc just getting it to work. This also might be obvious for some people who use this program regularly.

Instructions:

1. Download full Nasomi and Install as normal.

2. Connect controller via Bluetooth to pc

3. Download/Open ds4windows and add a new controller profile under profile tab (name it ps4 or something else).

4. The most important part is to go to "settings" tab in DS4windows and tick the box "Hide DS4 Controller"

5. Now that you have this done click the controllers tab and then click "start" on DS4Windows and your controller should appear. Link the controller to your profile you made before (should be a dropdown box).

6. Open the NasomiXI folder wherever you installed it to (mine is on C:// drive) go into Final Fantasy XI folder and then scroll down to ToolsUS open that folder.

7. Launch FFXipadconfig as Administrator (make sure to run as administrator as your settings changes wont save otherwise).

8. Now click Preset Config E (this should allow xinput at the top) (sidenote: not sure if it is necessary to click E and you may just be able to change settings manually but have read it has helped others so just do it). (xinput is what lets you put controlls in directly from the gamepad)

9. You should now be able to click on the dropdown boxes when they are highlighted you can click a controller button to change them and alter the profile, test it (button at the bottom) and save the profile then you should be able to open Nasomi as normal and the controller work.

The problem for me was the config did not seem to be picking up the controller or responding when I wanted to input to the profile. I tried the test and and then did the "vibration test" and my controller vibrated so even though it wasn't responding I knew the config was picking it up. If this happens close down the config, go back to DS4windows and make sure "Hide DS4 Controller" button is ticked.

I hope this helps anyone wanting to use a PS4 wireless controller with DS4windows on Nasomi. (may work wired also not tested).

Thank you very much for this sir! You have definitely saved me time. I was screwing around all weekend with my ps4 controller and DS4Windows and re-configuring my settings the way you suggested fixed my connectivity and input-lag issue i was having.

Specifically, i changed the "Hide DS4 Controller" setting, and in ffxi config i used settings E as suggested.

Hmm, I tried the steps here but no dice. The vibrate button works but nothing responds to button presses. I'll have to try rebooting, I also think I did some wacky thing to get Dolphin or something to work and can't remember...

ok got it, I have a Logitech G13 that has what windows considers a controller built in, and FFXI (and PSO2 for that matter) absolutely crap their pants if you have more than one controller plugged in, so I had to unplug it. So if you're having problems, make sure you only have one controller plugged in!

Glad this helped some people Good advice on unplugging the other controller also.

I've also run into the "Unplug your other controllers first" issue too. You're not alone!