We have released an sv2 proxy called demand_all_in_one the binaries are available here:
https://github.com/demand-open-source/stratum/releases/tag/DEMAND

You can use it for testing the demand job declaration functionality, for now only available on the solo pool.

Since is not yet stable the proxy  fallback   to ckpool if it the user hash rate that read from the pool is 0 for more than 3 minutes.

In order to try block declaration you have to run a TP https://github.com/Sjors/bitcoin/releases/tag/sv2-tp-0.1.2

the is a patched bitcoin node so you run like it but you have to add the sv2 options
-sv2 -sv2port=8442  -sv2interval=30 -sv2feedelta=2000 port must be 8442

otherwise the proxy will not work
when the TP is ready you chain as synced and you see in the log sv2 thread start you can launch the proxy
the proxy require only one argument the address of your solo pool proxy_bin -a [address] for example demand_all_in_one_sv2-x86_64-linux-gnu  -a bc1qxy2kgdygjrsqtzq2n0yrf2493p83kkfjhx0wlh

then you can point your miners to ip_of_the_pc_that_is_runing_the_proxy:34255`