How to modify the texlive web-bundle used by Tectonic?

[doronbehar]

I'd like to use Texpresso with a different --web-bundle used by the Tectonic submodule. Is it possible to configure this during runtime? Or do I must modify the default bundle in the tectonic Git submodule?

[let-def]

In detectonic branch, I switched to using kpsewhich for finding files. This does not allow customization of the bundle but might be suitable as an alternative to your problem.

I might also introduce a new flag to select a custom bundle in the future.