As part of SERVER-74266, we ran several genny workloads in config shard mode to evaluate any significant performance regressions. Through that we found several performance regressions in the lookup and graph_lookup workloads.

After some initial investigation, it was not immediately clear whether the regressions were due to issues with the test setup (where the config shard's setup was not the exact same as a regular shard server's) or if there are actual issues with the config shard code. This ticket should investigate the root cause of the observed performance regressions in the lookup and graph_lookup workloads and determine if it's a test setup issue or an issue with the config shard code. 

For reference, here were the results from SERVER-74266 in a spreadsheet:
https://docs.google.com/spreadsheets/d/1l1LwDNAreDKoM6JjE0j2U3mzhgL0kUDOJXsMrZBj3tU/edit#gid=1114981944

Here is an example of the setup used for the genny workloads with a config shard:
https://spruce.mongodb.com/version/6481f437e3c331486c4f3c8d/changes?sorts=STATUS%3AASC%3BBASE_STATUS%3ADESC