I’m no expert, sorry.
It will be complicated, to check against spam. If you have the time to write some custom code to caldera, try an own honeypot. Just a hidden field. Perhaps the bots will use ist. This is quite simple. Perhaps with a condition to hide the submit button when filled out.
In addition to that, you could run a hidden field with the actual timestamp (use {date:U} as standard). Then do a check against this field while calculating the time it took to fill out the form (comparing now with the timestamp). Humans probably need 45 seconds to 3 minutes or something similar. Bots are much more faster … ??
That could be an idea. Soon there will be an update to Caldera 1.8.0 … late beat is in revision … perhaps it changes something to reduce spam.
/st3phan