Tomato landrace

I am reading Joseph Lofthouse's book on landrace gardening and I want to start, with tomatoes of course. We just moved from a cool temperate mountains climate with frost to a warm temperate  seaside climate without frost (mangoes grow here, about USDA 10, North or Newcastle).  It's winter and the temperature is similar to the temperature when I used to plant my tomatoes out beginning of October in the old place (Australia).
I want a landrace (or two) and wonder how to start, I've never done it. How many aims could I pack in one landrace?
One thing I can imagine - if that is possible at all - to have year round tomatoes (or most of the year).
The other thing worth breeding for is fruit fly resistance. And of course the usual things like taste yield...
Also in Australia we have el nino and la nina. At the moment it is extremely wet. And this goes in 6year cycles. That would mean a landrace would be good after 10years or so?

My limited understanding is that tomatoes are particularly tricky to breed because of so many generations of inbreeding. Though if I can hope, I also wish to make a landrace of tomatoes one day too.

I think you could probably manage year round tomatoes in zone 10. They're grown more or less year round here in hot houses. If you have access to a greenhouse it can help with several of the challenges with tomatoes and mitigate your wet weather spells.

Here also most people avoid growing them without some kind of cover because we get heavy continuous rain from monsoon and typhoons.

with any luck, joseph lofthouse will chime in, since this is a specific interest of his. i think the issue is that most modern tomato varieties are built more for self-pollination: stigmas that don’t stick out, small flowers that aren’t too interesting to pollinators, etc. i.e. the opposite of the promiscuous pollination that helps a landrace be a continuous reshuffling.

here’s one of the threads about it:
https://permies.com/t/promiscuous-tomatoes

I am reading Josef Lofthouses book. I really like the idea. I never did seed saving because it seemed to be so cumbersome. i know tomatoes are difficult but this is the most important crop in any garden, who cares about silverbeet and turnips? Would they come as different colours and shapes? I'll have a read in the thread mentioned.

When tomatoes were domesticated, they lost more than 95% of their genetic diversity. They are one of the most inbred crops that we currently grow. That makes them particularly difficult to use in a breeding project, because they don't have enough genetic diversity to start with. They can't shift much in response to new conditions. They are what they are, and all the breeding in the world won't change them into something else. At most, we get slight modifications to existing varieties.

Thousands or years of inbreeding, and the genetic bottlenecks along the way, made domestic tomatoes highly self-pollinating. Every time a plant self-pollinates, it sheds half of it's existing diversity. For that reason, breeding with self-pollinating domestic varieties felt like a doomed undertaking.

The desire to do actual breeding with tomatoes, enticed me to incorporate wild genetics into my breeding projects.  I am selecting all varieties to carry the traits the require 100% out-crossing in every generation.