The extractor is now able to extract the ROM from the following Steam release:
https://steamcommunity.com/app/1368430 (Streets of Kamurocho)
For the extractor to work with "Streets of Kamurocho" please use the corresponding config.json from the "alternate_configs" folder.
Please note:
The Streets of Rage 2 ROM contained within the game has been heavily modified and is probably not very desirable for actual use outside of the game. This configuration file is here mainly for completeness sake.