I’ve found landrace seeds for the Candy roaster landrace here: Kürbis 'Candy Roaster' Bio Samen online kaufen.
The description says that the fruit have different shapes and the color of the skin can vary. This seems to indicate some diversity. Additionally, one member here even has a thread about his work with the candy roaster landrace: Modern Candy Roaster: Strarting from a legacy Appalachian landrace of Cucurbita maxima
So I plan to mix my own seeds from 2022 und 2023 together with these landrace seeds and plant a mixed patch in 2024. I plan to specifically use the Candy roaster landrace because it seems to be somewhat similar to the squash I bought and ate in fall 2022 (and saved seed from) so I hope it has similar qualities while also adding diversity.
I wish you luck in your direct seeding enterprise! And I am looking forward to hearing how your squash do on your heaps.