docs: update statements about speed

Author: mhucka

README.md

@@ -67,7 +67,7 @@ Please see the detailed [usage section in the Boffo documentation](https://calte
 
 ## Known issues and limitations
 
-Depending on your account type, Boffo will run into Google quotas limiting maximum execution time. For G Suite users such as the Caltech Library, this limit is 30 minutes, which ends up being enough for about 1100 items at a time. For non-G Suite users, the limit is 6 minutes.
+Depending on your account type, Boffo will run into Google quotas limiting maximum execution time. For G Suite users such as the Caltech Library, this limit is 30 minutes. For non-G Suite users, the limit is 6 minutes. At the time of this writing, Boffo can retrieve item records at a rate of about 70--100/second, so the time limit will limit non-G suite users to looking up somewhere between 25,000--35,000 item records at a time.
 
 
 ## Getting help

docs/known-issues.md

@@ -4,4 +4,4 @@ This section lists limitations and other issues known to exist in Boffo at this
 
 ## Execution time limits
 
-Depending on your account type, Boffo will run into Google quotas limiting maximum execution time. For G Suite users such as the Caltech Library, this limit is 30 minutes, which ends up being enough for about 1100 items at a time. For non-G Suite users, the limit is 6 minutes.
+Depending on your account type, Boffo will run into Google quotas limiting maximum execution time. For G Suite users such as the Caltech Library, this limit is 30 minutes. For non-G Suite users, the limit is 6 minutes. At the time of this writing, Boffo can retrieve item records at a rate of about 70--100/second, which translates to somewhere between 4200 and 6000 records per minute.