With the forum attachments hiccups going on I forgot to post a few comments about the update.
After much deliberation I opted to leave the CreatureTrigger as-is regarding EvaluateAll, because the code and code comments leave the original intention up for interpretation. Instead, as hinted at and mentioned in the change list, I added the ability to make custom trigger types through scripts. In the spirit of "... Teach a Man To Fish, and You Feed Him for a Lifetime".
In the script samples I already included two custom triggers. One that triggers when all creatures are dead, which effectively is the working replacement for what a CreatureTrigger with "fixed" EvaluateAll would've been.
The other is location style trigger that supports multiple creatures, based on an example machf posted earlier. That was only an example not necessarily a request, but I thought that was as good as anything to demonstrate the possibilities.
If you need something similar but slightly different logic then you can just copy that script and modify it. You can also ask and I'll try help if it's not some super complex trigger code that takes hours

Once you have a trigger script, the use is very simple. It works like any other trigger in terms of T-scripting. The only difference is that the class is CScriptTrigger and you have to specify a Script param with the script name.