Actually you can't redirect DevFee for SIA.
I suppose Claymore will take just the 1% of it because the other 1%, if you'r mining dual ETH+SIA, will be redirect on your wallet.
It does not have devFee for Sia as I know, it has 2% devFee Ethereum mining not 1%SIA + 1% ETH, it works two times longer for Ethereum so with this software you will get back your Ethereum HashRate