Unfortunately, it is currently not possible to customize the main asset page, so manually adding the value from the SMBIOSAssetTag to one of the asset custom fields would be the only workaround currently.
We've already received similar requests from our user base to add a customization feature for the main asset page, and as such, it was added to our customer wish list. We have noted your forum post to add weight to this. Features on our customer wish list get development priority based on a combination of customer demand and difficulty to implement. As such we aren't able to guarantee that this feature will be implemented or provide you with an estimated release date at this time.