- Add a configuration option for always using the "userinfo endpoint" for OpenID Connect. This fixes support for some identity providers, e.g. GitLab. Contributed by Benjamin Koch. ([\#7658](https://github.com/matrix-org/synapse/issues/7658))
- Allow`ThirdPartyEventRules` modules to query and manipulate whether a room is in the public rooms directory. ([\#8292](https://github.com/matrix-org/synapse/issues/8292), [\#8467](https://github.com/matrix-org/synapse/issues/8467))
- Add ability for`ThirdPartyEventRules` modules to query and manipulate whether a room is in the public rooms directory. ([\#8292](https://github.com/matrix-org/synapse/issues/8292), [\#8467](https://github.com/matrix-org/synapse/issues/8467))
- Add support for olm fallback keys ([MSC2732](https://github.com/matrix-org/matrix-doc/pull/2732)). ([\#8312](https://github.com/matrix-org/synapse/issues/8312), [\#8501](https://github.com/matrix-org/synapse/issues/8501))
- Allow running background tasks in a separate worker process. ([\#8369](https://github.com/matrix-org/synapse/issues/8369), [\#8458](https://github.com/matrix-org/synapse/issues/8458), [\#8489](https://github.com/matrix-org/synapse/issues/8489), [\#8513](https://github.com/matrix-org/synapse/issues/8513), [\#8544](https://github.com/matrix-org/synapse/issues/8544), [\#8599](https://github.com/matrix-org/synapse/issues/8599))
- Add support for running background tasks in a separate worker process. ([\#8369](https://github.com/matrix-org/synapse/issues/8369), [\#8458](https://github.com/matrix-org/synapse/issues/8458), [\#8489](https://github.com/matrix-org/synapse/issues/8489), [\#8513](https://github.com/matrix-org/synapse/issues/8513), [\#8544](https://github.com/matrix-org/synapse/issues/8544), [\#8599](https://github.com/matrix-org/synapse/issues/8599))
- Add support for device dehydration ([MSC2697](https://github.com/matrix-org/matrix-doc/pull/2697)). ([\#8380](https://github.com/matrix-org/synapse/issues/8380))
-Implement[MSC2409](https://github.com/matrix-org/matrix-doc/pull/2409) to send typing, read receipts, and presence events to appservices. ([\#8437](https://github.com/matrix-org/synapse/issues/8437))
-Add support for[MSC2409](https://github.com/matrix-org/matrix-doc/pull/2409), which allows sending typing, read receipts, and presence events to appservices. ([\#8437](https://github.com/matrix-org/synapse/issues/8437))
- Change default room version to "6", per [MSC2788](https://github.com/matrix-org/matrix-doc/pull/2788). ([\#8461](https://github.com/matrix-org/synapse/issues/8461))
- Add the ability to send non-membership events into a room via the `ModuleApi`. ([\#8479](https://github.com/matrix-org/synapse/issues/8479))
- Increase default upload size limit from 10M to 50M. Contributed by @Akkowicz. ([\#8502](https://github.com/matrix-org/synapse/issues/8502))
-Support modifying event content in `ThirdPartyRules` modules. ([\#8535](https://github.com/matrix-org/synapse/issues/8535), [\#8564](https://github.com/matrix-org/synapse/issues/8564))
-Add support for modifying event content in `ThirdPartyRules` modules. ([\#8535](https://github.com/matrix-org/synapse/issues/8535), [\#8564](https://github.com/matrix-org/synapse/issues/8564))
- Limit appservice transactions to 100 persistent and 100 ephemeral events. ([\#8606](https://github.com/matrix-org/synapse/issues/8606))
