I have actually been running tests all night long, creating several new characters and testing out the lip adjustment in the Character Creation window to lower the white glare effect on the lips from lightning and shaders in various areas.
I am counting at the moment 15x playthrough states in my tab, of which 11x are labeled as "Deleted" to differenate between my 4x actual saved games-in-proress and the 11x that served only to test out characters in-game (and those 11x saved games I deleted in-game after my testing concluded).
As far a I can tell, there seems to be no limited as to how many playthrough states can be listed and each saved game did produce a playthrough state with my character's name, class, gender and race referenced (with the exception of one, which I will write about at the end of this text).
However, whether there is truly a limit as to how many playthrough states there can be, is anyone's guess. 20, 30, 40, 50? Who knows, but it would take a long time to test that out and to see, which I am not planning to do.
Not entirely sure why your having issues with saved games not producing correct playthrough states in your Dragon Keep window. Maybe a glitch? I did notice one thing however last night.
On one of my test runs in-game, after the character creation, I skipped through the cinematic and the dialogue animations with Cassandra etc...to quicken the process of getting to the bridge after you get out of the dungeon at the start, so I could inspect my characters looks and lips etc...
I saved and exited and logged on Dragon Age Keep on my PC and noticed that my saved playthrough state did not list my character, just the two heroes from DAO and DAII.
So then I asked myself why my character was missing in the playthrough state. And I decided to stop skipping through the cinematic and dialogue animations when running a new started game. I also saved each new game a few times and then logged out.
I logged back again into Dragon Age Keep to see if my newly started characters and their referenced playthrough state appeared as it should (with name, race, gender and the picture) and it did, for all the ones I created after the initial one, while running test game runs.
Hope that made sense what I wrote here and perhaps that may have caused that problem, skipping through the cinematic and the dialogue animations when pressing "X". (I'm on Xbox One).
In any case, I do have my 4x game-in-progress now setup, which I each play, depending whether I am in the mood to play my Elven Warrior or Human Mage etc...
If I am to make a new character however, I will make sure after exiting the dungeon at the beginning and after saving, that the playthrough state in Dragon Age Keep reflects everything as it should, namely; my character's picture next to the two heroes from DAO and DAII and my character's name, race and gender.
Hope what I wrote here may have helped a little.