You’re definitely not the only one that wants something like this
I think the problem is Home Assistant relies on capturing sensor data in real time and then writing it to the recorder database, like an old school tape deck.
It appears currently the only way to get historical data in to a sensor after the fact is to manipulate the mysql recorder database itself, which is definitely beyond what I would know how to do. It does look like from the other thread though, others are working on a solution. Its a brand new integration and I’m sure development around it is definitely ongoing.