Lemmy is very much in its infancy as a product. And I suspect they may have been ill prepared for the reddit influx.
So far it seems to have held up surprisingly well thanks to the federated architecture.
At this point any thought into the topic is good. Lemmy is going to rely on people who do the thinking, the coding and the hosting if its going to survive as a non commercial product.
I’m about as far from being an expert as there can be but as a programmer I would say that the main consideration would be load… if you were to migrate the contents, is it 50 posts or 50,000. If its just users moving in and starting a new empty community, they can spread themselves over many instances anyway. But you still have to think about how much they are posting and how frequently.
I am not aware whether there are metrics available by instance as to how much they “can support”. Of course cloud hosted instances could expand infinitely, but are limited by the budget. If you anticipate a high load then perhaps talking to the instance owners of the larger ones would be appropriate.
On the flip side, the instance listing could include these metrics or instance owners could set a bio of what their capabilities are or what they can handle.
Another consideration would be what else they host… you don’t want to find your instance defederated for trolls or other nastiness in other communities. That said, if its an nsfw sub, you probably should go to one of the nsfw instances.
Had this myself recently, process explorer still works though. tskill taskmgr.exe would probably work too.