need an idea for switching workers between different currencies on sha256

I have a mining pool for sha256 algo,
we mine BTC, BCH, BSV, DGB, LCC, FCH, ...
basically we support all sha256 coins

what i'm trying to achieve is that :
in some pools , i can see that you can choose the coin to mine from pool's website (no need to change miners configuration)
for example you login to website and choose to mine BTC... and then afterward you choose to mine BCH or .... (no need to change miners configuration)

i'm looking for a way to implement it based on miners username(workername), how can i switch users' hash-rate between my different pools

I tried to use a forwarder , the problem is that in stratum protocol, at first miner send "mining.subscribe"
later miner send "mining.authorise" , with it's username

if i can trick the miner to send "mining.subscribe" again 1 more time after "mining.authorise" then now i can decide to which pool should i forward the miner.

I'll appreciate if some one can help me with an idea