At this point I don't believe you can hurt anything by running it but if that upper bearing is indeed galled it will most likely seize again. But who knows? It might run fine for a long time.
I have also seen some 7000 series engines wear the upper main to the point of the hole being oval and then the crankshaft is running at an angle damaging the flywheel, the charging stator and the ignition module so if you do run it you might risk ruining those components at some point in the future.
It's been a while since I've dealt with a 7000 with a seized upper main bearing and I wasn't sure I was remembering the issue correctly so I made a phone call to refresh my memory.
There were a few of things that were causing seized upper main bearings on the 7000 series engines.
On the very early engines, Kohler accidentally installed Command series crankshafts in them and the top oiling hole on the Command crankshaft is different than on the 7000 series and that was causing the upper main bearing to not get proper lube and seize.
There was also an issue with the alignment between the upper and lower main bearings being slightly off which was causing upper main bearing failures. A little too much tension on the drive or deck belts was also amplifying this alignment issue on some brands of equipment.
Typically on a full pressure lubed engine the first thing to happen in a low or no oil situation is one of the connecting rods will seize to the crankshaft which is why I stated that the dipstick not being in all the way probably didn't cause the failure on this engine even though it was undoubtedly low on oil. The more I thought about that I started to remember that there was something about the lubrication path on the 7000 series engine that made me doubt myself and that's when I made a phone call to someone who knows and I stand somewhat corrected. The upper main bearing on the 7000 series is the last to get pressurized oil in that system so theoretically it could be the first to go due to a lack of proper lube situation. With a proper aligned crankshaft and no excessive tension on the belts the a typical failure due to a lack of proper lube could still be a connecting rod seizure.