Your best bet for getting people to use it more, would be adding a secondary algo that isn't already covered by Claymore
Unfortunately, the set of algorithms that can be dual-mined efficiently with ethash (they should be compute-constrained, not memory bandwidth-constrained like ethash) is rather small.
If considering sia for dual.... please also consider those coin for single algo mining ..... like i can run sia solomining on my rig.
We will have a parameter to adjust the relative speed of ethash vs the secondary coin (decred, sia, etc.) but it won't go all the way to 100% secondary coin and 0% ethash.