Unfortunately it's hard to say without being able to envision the full context of the kitchen, the house, and the user. Without trying to be coy or ambiguous our answer is, it depends.

I don't know that there are any hard, fast rules in design. It seems that whenever a hard and fast rule is established, some sly designer comes up with a ingenious design that contradicts that rule entirely, usually just to spite the rule. So, in our opinion, no there are no rules to prelude stainless steel counters.

The more important questions is, what is your intention. We are minimalists when we can be. We like to keep the material pallet simple; less is more. Often we consider keeping the counter material the same throughout unless a certain counter is deliberately different [in function and aesthetic] from it's counterparts [forgive the unintentional pun]. If it is meant to be different then we ask if it should be subtly different to create a resonating nuance of tension, or if it should be highly contrasting to be visually playful and impacting. The subtle approach is much more difficult to pull off.

Short answer: it all depends.

This unique home is a joy to behold and, I'm sure, a joy to live in. Congratulations!

Crush, we very much appreciate the compliment. Cheers!