Yes, reasonable points. I do think that there is a mediating size variable here. E.g., for organizations with sub-$1m budgets, having the knowledge that others would/​could donate if you need it might be more optimal than diversifying, due to the time costs of doing so. I do think the x2 time is a lower bound, as some funders might take ~x10 more time, and you are more likely to put up with them if you are seeking diversification.
Yes, reasonable points. I do think that there is a mediating size variable here. E.g., for organizations with sub-$1m budgets, having the knowledge that others would/​could donate if you need it might be more optimal than diversifying, due to the time costs of doing so. I do think the x2 time is a lower bound, as some funders might take ~x10 more time, and you are more likely to put up with them if you are seeking diversification.