Might be a Stupid Question

I am looking at getting a Legion Go S, Z1 Extreme edition. There are two used ones I have narrowed it down to. There is a Steam OS version on offerup for $750 and a Windows version that has had steam os installed for $650 on ebay (this is fine). If I buy the white version w/steam os am I missing any functionality from the native steam os version. I believe the purple/navy version has a dedicated steam os button, is there a way to replicate that function on the white version.