From there we are changing Patterns and Sounds temporarily (for a limited period of time; not permanently) Remix keys remain the same, if any, until we add or remove one and save Preset.
So if we like the pattern or sound difference we can then press a Remix key and save or just save.
Even with an ‘Empty’ preset slot like in your uploaded image we can still save what we like or add Remix keys and save.
PB4 Absence is the Preset I am pointing to with ‘Load Pattern’ and ‘Load sounds’ as the options, not the ‘Empty’
As I said before, Loading a Pattern does not include the ‘Remix Keys’. If you can do this, can you show how?
I make a Pattern, then Randomize that Pattern, Press the Remix Key to store that Pattern…I do this a few times! Then I save as a Preset.
What I expect to happen, when I Load a Pattern, from the menu with ‘Load Pattern’…‘Load Sounds’. Is the Pattern to load, with the Remix Keys.
My Point is that I want the Remix Keys to be included with the Pattern. Not to create new Remix Keys, as Playbeat 4 will create Totally different ones, from the ones I want to re-use.
This happens because the pattern from the ‘X’ preset is loaded into another active ‘Y’ preset, which may already have stored remix keys. It wouldn’t be ideal to overwrite them with this control. Perhaps we could add a third option to load patterns along with remixes.
That would be Great! 
Can you import midi in the trial version.