Thank you for your feedback. There are no plans to add functionality to K2 Cloud for natively importing Excel data into a SmartObject. However, if the community-based broker is rewritten to use the new JavaScript Service Provider type, then it can be used in K2 Cloud.
Other low/no code platforms support this natively. It's not terribly difficult...the code even exists already in the community broker! Just do it!
This is a big one we miss too. We have to use PowerAutomate. It's a shame that we have to cannibalise the toolset and give an odd user experience.