I'm glad to hear that at least some of the issues you saw have been solved with the latest updates.
jula Alt+Tab window preview is sometime broken.
This is something that would need to be reported to the KDE folks through a bug report (if there isn't one already) on the KDE bug tracker . This is a problem with Plasma that Solus can't fix.
The loading times with Unreal is, as you suspect, probably caused by asset loading.
As far as the task manager, a couple of things
- It should show windows previews (and I see them on my system) if set to do so. If previews don't show up, check the settings.
- The settings also control what clicking an application does
Right click the task manager and click "Configure Icons-only Task Manager" (or Icons-and-Text, depending on which one you have)
"Show small window previews..." needs to be checked to show the previews.
Now click "Behavior" on the left and check what you have set for "Clicking grouped task"