TYPO3 Core

I use this feature to not need many clicks, but only scroll downwards.

It also depends on usage. I use that feature in list view very often, eg to set a page property for all subpages. Then i scroll down and edit nearly every record one after the other. Very useful, and any collapse would disturb this way of quick edit.

For the distinguishing - i would prefer alternated bg colors like in a grid instead of tabs or collapse. While you're edit you won't use the mouse, so cool would be:
TAB to jump to next form field
CTRL+TAB to jump to next record form field

For real improvement of usability I suggest an additional solution 3. It's not about layout but funtionality. So I'm not sure if this is the right place for posting or if I should better create a new issue.

Imagine you have to insert the same data into 20 manually chosen records. Why would you want to scroll, click and edit all the 20 records? This is highly inefficiently.

=> It should be possible to edit all the 20 records at once.
=> You should be able to decide wether you want to overwrite all existing data with the new value, delete data or to add new values.

E.g.: You create a new tt_news category 'dogs'. There are already 43 articles regarding dogs. After manually hooking these articles you just click something like 'edit all at once [add values]' and chose tt_news cat 'dogs'. Done. Spend your working time on more difficult tasks.

The old way is only reasonably if you have to insert different data into each record.

For me it's like what Steffen Gebert wrote: I'd prefer to not need many clicks.