Ergonomic basses

[Bass Iniya]

I have a steinberger 4 string and it is one of the less confortable basses I have ever had.
If you don't like Neckdive, forget about those.
It is not really due to the body shape but the "upper strap button" is so far from the headstock point that I am always fighting the get the bass headstock up and closer to me, It is a barking nighmare.
The most ergonomic basses I have seen are some custom Conklins and Basslabs and some 30 scale basses with modified upper horns (or extensions).
In fact, you can just take any bass you like and screw a longer metal (aluminium is light) plate under the upper horn which sticks out towards the headstock any the distance you want, then, you drill some holes on the plate to screw the strap button and you try where it's more confortable for you.
The plate needs to be siff enough to not bend too much and the closer to the neck it is, the less you need to lengthen it towards the headstock.

 

[ixlramp]

any jazz bass really

This is funny, old fashioned Fender shapes are not remotely ergonomic. When they were first released they were revolutionary, but that was decades ago, we can do much better now (but mainstream instruments do not, and have regressed since the 80's).

In these 'ergonomic bass' threads many fairly normal bass shapes are recommended, any remotely normal (modernised P/J bass) shape is not ergonomic, it requires a radical redesign.