Well the answer needs a bit more explaining.
So the short answer is yes you can change all of the views like you were used to. However, the long answer is, it depends what you are going to edit.
To explain it better: if you configure homekit infused at the global level (which is a folder with files I have included) you can update easily into new versions. If you configure it at view level you must read update notes which can as you already know be a lot of information with a lot of changes.
Now my new documentation states the following: if you want to edit views, you are better off copying them and then change the buttons paths (with global_config) to point to your custom view. Just name your view to anything but the original name. This way, when an update comes you can simply overwrite the old stuff (as your configuration comes from global_config, which I will only update if it is absolutely necessary). Also editing templates I advise you to do the same. Copy and rename a template.
I do no longer use decluttering-cards which is a good thing for older users of HKI, why? Well because you can simply copy/paste old config to new views. Though you MUST change the folder those templates live in (they can NOT be in /lovelace/templates/) so rename the folder with decluttering cards to something like ‘lovelace/decluttering-templates’ and then change the reference in ‘ui-lovelace.yaml’. That is all for now.
I also have to mention that 90% of the views can be autofilled (which is the default setting now) this means if you have less knowledge of home assistant it will still be super easy to install and use this.
Also, I will update the project to version 2 in the upcoming week which will be even more awesome than it already is as it will receive some major new cool stuff like hiding/showing different kinds of elements from the interface (see screenshots below). With this update, it will probably (not sure if it will make it in time) have the choice between the current device type based views and room based views.