We are looking for new defined contribution health plan software (including HSAs, HRAs, and even FSAs). Does anyone have any thoughts/experiences/recommendations they are willing share?

This doesn't directly answer your question, but an HSA must be held, basically, by a bank or an insurance company as trustee (IRC Section 223(d)(1)(B)), so I don't think you'd need software for that. Remember, an employer doesn't maintain an HSA (like it might maintain an HRA or FSA), and has no administrative responsibilities with regard to an HSA, even though the employer may contribute to the HSA of certain employees (who can hold or move the HSA wherever they choose).

Software to automate what aspect ?

Why and for use by what sort of business ?

Obviously you are not a TPA and a sales rep would be representing someone who was already equipped. Maybe we do not understand your definition of defined contribution health plan.