Any take on this...how to replicate a step mash regimen with a single temperature infusion mash?
If you take a specific step mash regimen and think about what each of the steps is trying to accomplish, you can use your knowledge of ingredients and mash chemistry to decide on a process that will work well in most circumstances. However, there are some steps (such as a ferulic acid rest) that you probably can't really replicate (though proper yeast selection and fermentation management may help).
If you post a specific step mash, someone will be able to suggest an appropriate single infusion mash temp.
You can always use your boil kettle or HLT as a direct fire mash tun to perform a step mash and then transfer to your regular mash tun for lautering (or use boiling water, perform a decoction, or set up a RIMS or HERMS system).