Hi @casparwylie, as described in other threads here, deleting Let's Encrypt files or certificates will not affect the rate limits. The rate limits are enforced on the CA based on the total number of certificates issued, not based on which certificates are in use (or in your possession or unrevoked).
Deleting your existing certificates or LE client installation will not allow you to get new or different certs any faster. The main certificate limit will reset after 7 days, regardless of what you do or don't do:
In the future, you can try using --staging to get test certificates instead of production certificates (test certificates from the staging server don't count against your production server rate limit), or --dry-run (starting in client version 0.4.0) to get test certificates without installing them (to verify that the CA would be willing to issue the certificates you request using the verification method you plan to use).