I can only speak for myself (I’m not sponsored by Omni), but while it’s totally fair to criticize the app, this is a user forum, so I can only help people use the app as it is. I have no idea what features may change or come later, so I can only suggest how people might get the most from the app as it works right now. Only Omni can speak to how that might change, and so using their support channels (email moslty) is ideal.
As for the question of inheritance, the way I have always interpreted it is that projects are containers for actions that lead to a common outcome. If that container is due at a certain time, then the outcome must be due at that time, then the actions must all therefore be due at that time (or sooner).
If the container is deferred to a certain time, it means work on it cannot start until that time, so all actions must also be deferred until that time (or later).
If the container is flagged door importance, then its contained actions must also be important, and so are also flagged.
Tags, however, feel like they operate at the action level. If my project is to build a shed, I’ll probablay need to get materials, make calls, get quotes, acquire permits, etc., so not all of these things are things I would tag the same way, because I wouldn’t act on these things in the same contexts/priorities, etc. in the grand scheme of all my other actions. Personally, I avoid tagging projects, because I generally don’t want my actions inheriting.
Again, this is my workflow only, and how I see inheritance working. I am not defending anything, I am merely explaining how it works and how I use it. Who knows if/how things might change in future with the advent of tags.