At least with that extra information I now sort of understand where you are coming from.
However…
I still don’t think that using packages with lovelace is the answer for at least a couple of reasons.
the first and foremost is that packages can’t be used with lovelace because packages interact with the backend. Lovelace configures the frontend. the two aren’t supposed to overlap at all. Which is the reason the switch to lovelace was made in the first place - to disconnect the backend from the frontend. So lovelace packages won’t happen as far as I understand things.
Second, you already made a decision to configure the frontend using yaml when you created the frontend config using group views/card in packages…which used yaml…
I see no difference between “enforcing” a decision for your users to use lovelace in yaml mode and forcing your users to use the older states ui which by default always used yaml mode.
At least now the users have the opportunity to get the benefits of the newer, more flexible UI. Even if they are still “required” to use lovelace in yaml mode.
As I said, I use lovelace in yaml mode and I don’t think I’m “deprived” in any way of the functionality of using lovelace in that way at all.
And, again, since you can use !include statements in your lovelace in yaml mode it makes it dirt easy to drop a new yaml file that contains an entire view into a designated folder (that you decide where it goes) and add a single line to the ui-lovelace file to include that lovelace view into your frontend.
Obviously I don’t know exactly how your project works but I can’t see how you couldn’t rework a lovelace view to work with it.
Maybe I’m completely wrong tho.
The other thing is that I don’t get is why you can’t still use packages in some way to do what you want.
The old states ui just used groups that you manually created to create the ui. You can still create those same groups in those same packages right now. The only thing you are losing is the “view:” option of the groups.
Maybe if you posted what you think might be limiting your ability to do what you used to do with the states ui then maybe someone might be able to help you figure out an alternative way to accomplish the same thing.