Bavaria-filaments.com offers 4x250g spools in 1kg package with different colors,
it works for 250g Bavaflex TPU Super Soft black too.
These are very small and I have constructed an adapter for it.
This is reusable and the two halves of the adapter are kept very light
and thus doesn't consume much filament in the creation.
They are suitable for most filament rollers and the Bambu Lab AMS.
Rewinding is no longer necessary.