I hear you, and if this was Lightroom then it would be a simple matter of Remaining the Filter for example, add the Tilda Symbol ~ in front of the Filter name.
But, this is Photoshop and I’m afraid it’s not as simple as renaming the Filter or sticking all the Topaz Filters into a single Folder and hoping it’ll just work.
By all means, you can try that but, I’m not going to tell you how because, there may be some kind of deeper coding within the Filter which we are blissfully unaware of plus it’s risky and may break the Filter so, you can understand my reluctance.
All is not lost though, one alternatively you may not have thought of is creating Keyboard Shortcuts for the Topaz Filters for example you could have the Control key plus the Shift key plus the P key for Topaz Photo
Simply press Control+Shift+P= Topaz Photo
Here’s how to create Keyboard Shortcuts
Go to Edit Menu then, Keyboard Shortcuts.
Then, set the Shortcuts to the Application Menus.
Then, scroll down to Filter and find your Topaz entries.
Then, finally Assign a simple yet memorable Shortcuts for your Topaz Filters.
This allows you to bypass the messy menu entirely.