Legacy is dead. Long live legacy.

I've been following traccar project for many years, and I've been been using almost all it's features depending on the situation.
I have legacy and moden web app generally both served on same traccar API server, so I can easily compare the two.

I think that modern UI is nice but not as good as legacy one, and seeing it dropped from installer in 6.x makes me want to never upgrade from 5.12.

What's wrong imho with moden UI? Top 3:

• bad multi-select input control: where legacy had a list of checkboxes, modern has dropdown menu. Have you avere tried to link 3 geofences to 10 devices? It is no less than 80 mouse clicks/taps with modern, ~40 with legacy. Same problem when enabling devices on specific users on any user task that require interaction with multi-select input field that can get big.
• rotating icons on map: where legacy has rotating arrows showing device on move, modern has POI icon. That's simply wrong for a GPS tracker.
• less efficient use of display space: table-based lists of stuff in legacy UI returns gives more in same amount of space

There are many pros for sure, like the "replay" feature and generally the whole reporting thing, but for a steady use legacy feels more professional and polished than modern.

Do you think modern is really ready to replace legacy?

You can continue using legacy app if you prefer it, even with 6.2.

Yes, but with 6.x legacy has just stepped outside the installer.
The "transition" is period is over, It just went from veteran status to second class citizen.

If a new feature is introduced into API, how can I know that legacy won't be left behind (it probably already is somewhere)

It is definitely left behind and doesn't support many of the new things.

Is there deliberate intention to not break legacy UI compatibility on traccar API upgrades?

There's general intention to not break backwards compatibility of the API, but it's unrelated to the legacy app.

But it's not a guarantee.

Thanks for the answers.
I'd want to ask you to write in changelog/blog post when legacy will stop being compatible with Traccar, if possible.
Thanks

That's for you to test. We won't be explicitly testing compatibility. Let us know.

Long live legacy! :P

I personally think Modern is pretty good, It does have its limitations.

Since this is an open source project that can be easily over-come with user contributions.

I agree with the author of this post, the "connections/permissions" management can be improved. Hopefully someone will share or contribute to improving it.