Yes, it is possible.
You want to use Groovy’s feature called “ExpandoMetaClass”. Read the doc:
https://www.groovy-lang.org/metaprogramming.html#metaprogramming_emc
I have applied this technique to my Katalon projects several times. See the following post for example:
Be informed, in order to utilize the “Metaprogramming” technique, you need to read the source code of katalon studio WebUI API. I described how to get the source codes in the previous post