Catalogues can do this. I was actually planning to create a new block similar to the catalogue contact us form block which can render a catalogue as a form, but instead of exclusively e-mailing results, it would operate as normal by saving the results into the catalogue as an entry.

I don't think it's necessary to reinvent the wheel and make this a separate feature when catalogues are more than capable of doing this.

The block is planned for v11.

Sounds good to me, adding the entry to the catalogue makes much more sense.

Implemented in v11

Oops, thanks for marking this off for me.

(for reference, it's main_catalogues_form)