As noted in the Roadmap thread https://www.wilderssecurity.com/threads/sandboxie-roadmap.445545/page-8#post-3187633 build 1.14.0 should get the Proxy injection feature which until then was only available in the private Patreon Insider-Build. As this is a feature which is not a typical Sandboxing functionality but rather a replacement for a 3rd party tool its usage will be contingent on having a Advanced Encryption Certificate, which will be re labeled to eider Advanced Privacy Certificate or just Advanced Certificate. Since the introduction of the Advanced Encryption Certificate was not universally received positively, I think its prudent to announce this development up front. Also please note that initially there may be some inconsistency with regard to usage of this feature, for patreons it should remain available in the great patreon tier, but this may not be enforced consistently in the early builds.
Why are you introducing the feature if it wasn't received positively? Do you feel it is right to introduce features which are not a functionality of Sandboxie?
Not the Encryption feature was received not positively but the requirement for an additional certificate. Yes because these Features benefit from Sandboxing and or vice versa. In case of the encryption Sandboxing helps in isolation. In case of Proxys its beneficial to have not just global rules but per box rules.