I’d like that too, perhaps just change the color of the “you can jump here” highlights depending on whether you will win or lose the battle if you jumped there (taking into account any ships you can scan that are headed for that star, and the star’s production).
Likewise, when there are fleets jumping to your star it would be nice if you could just glance and see if you would win or lose, taking into account your production and all the ships you can scan which are currently jumping to it.
I’m sure there will be folks who say taking that all into account is part of what makes a good player, but it’s boring – seems like the game should be about the decisions you make not about the numbers you crunch.
Caveat: when I do these calculations I always add one to my opponents weapons level, just in case. I’d want to be able to have this mechanism do so as well.