AbstractOTDPlugins VS VoiDPlugins

It's about 0.43 on the Reconstructor anti-smoothing scale. Hawku's smoothing doesn't really convert well into EMA smoothing. You can try to understand now EMA smoothing work by reading through the code of this OTD plugin

Another thing you can do is in OpenTabletDriver, go to the Plugins window and look for the WindowsInk plugin. You might need to get a driver called VMulti as well. Instructions here https://github.com/X9VoiD/VoiDPlugins/wiki/WindowsInk

- Install and follow instructions from WindowsInk's wiki

There is a plugin for that, however it is highly unlikely that you will be able to get any usable pressure data out of that pen, since the tablet is expecting a different pen for that. But if you want to try, you need to download this version of the driver and follow these instructions. Almost certainly won't work due to having the wrong pen, but worth a shot.

- You can use the Windows ink Plugin to get pressure in apps that are compatible with it

Enable Pressure support on Windows: https://github.com/X9VoiD/VoiDPlugins/wiki/WindowsInk

I'd ask on OTD's Discord for more specific help for that driver since this subreddit is more of general Wacom help, but chances are you haven't installed vmulti and the WindowsInk plugin for OTD, which allow you to use pen pressure. There is a setup guide here.

You should use OpenTabletDriver, not Hawku. Hawku drivers are extremely outdated and buggy which is probably why Windows Ink mode on there isn't working properly for you. OpenTabletDriver does not support pen pressure in its default pluginless state, but you can easily install the Windows Ink plugin in plugins>plugin manager. In order to set this plugin up properly, please read all the instructions listed here. Once installed, pen pressure should work fine for art. You can also install smoothing or antichatter filters to preference, if needed. The art settings probably are not ideal for osu, so you can save a separate art and osu settings profile by exporting settings with file>save settings as. You can then press file>load settings to swap between the two.