Whether a checker will time out for a given cacher or not depends on a combination of of how that particular checker is written and how many finds the cacher has as well as (at least in some cases) the exact combination of finds that cacher has.
I have run many checkers for people with six-digit number of finds successfully. It's not impossible as such, but some checkers are more complicated than others and may need to resort to performance-enhancing tricks in order to accomodate cachers with a high number of finds.
These two checkers are about finding any of a long list of words in the cache titles of caches the cacher has found. This means that the script needs to do a loop within a loop and that may quickly get ugly, performance-wise.
In order to solve this, you need to talk to the script writer (GentlePurpleRain) and ask if the script can be better optimized (it's the same script for both challenges). (I'll also note that this is something of a corner case since this type of challenge is no longer allowed for publication.)