与gateway适配的sentinel支持熔断后的基于fallbackUri的降级吗

1.就想问问spring-cloud-alibaba-sentinel-gateway 这个依赖目前降级只能在统一的地方（BlockRequestHandler）处理吗，是否支持针对url级别的降级处理。
2.如果我想要在BlockRequestHandler 实现类的handler方法里面进行fallbackUri的远程调用有什么好的方法吗。

Start by examining the spring-cloud-alibaba-sentinel-gateway integration and the BlockRequestHandler handler method named in the issue. Determine whether fallbackUri can be selected per URL and whether remote fallback calls are supported there; done means the supported behavior and configuration are documented or implemented with a clear example.

Written by the indexing model from the issue text.