Joining from getin_request is fine during burst, it will just queue.

doc/UPDATES.md

@@ -11,6 +11,7 @@
     clients who are opped in 'set homechan'.
   * Some small performance improvements.
   * CPRIVMSG/CNOTICE/TIME/TOPIC/OPER should end connection bursting on ratbox.
+  * Fix server connect bursting for joining channels with help from other bots.
 
 # maint
   * Clear FiSH keys when a client quits.

src/mod/irc.mod/irc.cc

@@ -678,11 +678,6 @@ getin_request(char *botnick, char *code, char *par)
     return;
   }
 
-  if (connect_bursting) {
-    putlog(LOG_GETIN, "*", "%sreq from %s/%s %s %s - I'm in connect burst mode.", type, botnick, nick, desc, chan->dname);
-    return;
-  }
-
   if (server_lag > lag_threshold) {
     putlog(LOG_GETIN, "*", "%sreq from %s/%s %s %s - I'm too lagged", type, botnick, nick, desc, chan->dname);
     return;