Even if it were after applied reinforcement, on top of a repair of the crack itself, the quality of the welds on those plates would make me question the quality of the full-pen weld on the frame.

Sometimes social media posts don't convey proper
context or information. Sometimes a picture is not worth a
thousand words. The frame on the Emma Nevada was cracked through a bolt hole. The Nevada Central only surface-welded the crack. There was even rust and dirt under the weld. We v-notched out the crack on both sides up to the depth of the bolt and full-penetration welded one side at a time. The reason we welded on the plates is because of the bolt hole, it being a weak spot in the frame. Most of the welding was done during the week and no one took pictures. Admittedly, the weld bead on the plates looks rough, and we may revisit those welds. If the experienced people examining the site do not think the cracked area needs the extra reinforcement, we can certainly remove them. The next step will be to finish cleaning the steam chest/cylinder casting and lower frame rail extensions and transport this to a vendor that specializes in large cast brazing. This is expected to take place towards middle of October. In the meantime, we will be installing the reinforcing plate at the bottom of the smoke box and cylinder casting interface. Then we will be able to start reinstalling the drive wheels.

From said Facebook page, a post by Mike Wissler

From said Facebook page, a post by Mike Wissler

I would remove the plates. Not because no reinforcement is needed, but because I would be embarrassed to have that there. Those welds can't contribute much. The plates aren't even symmetrical. As others have mentioned, ... you should get phosphorus and sulfur levels.