Examples of using the Caldera Forms filter caldera_forms_render_field_structure to modify field display when rednering forms, see: https://calderaforms.com/doc/caldera_forms_render_field_structure/

caldera_forms_render_field_structure-change-default.php

<?php
/**
 * Change the default for a dropdown to "red" if a specific user meta key is set for current user
 */
add_filter( 'caldera_forms_render_field_structure', function( $field_structure, $form ){
	//make sure to change field ID to your field's ID here!
	//not that $field_structure is not the same as field config, but that is stored in $field_structure[ 'field' ]
	if( 0 != get_current_user_id() && 'fld_1234' == $field_structure[ 'field' ][ 'ID' ] ) {
		if( 'red' == get_user_meta( get_current_user_id(), 'color', true ) ){
			$field_structure[ 'default' ] = 'red';
		}
	}

	return $field_structure;

}, 10, 2 );

caldera_forms_render_field_structure-change-value.php

<?php
/**
 * Change the value of a specific field based on a time comparison
 */
add_filter( 'caldera_forms_render_field_structure', function( $field_structure, $form ){
	//make sure to change field ID to your field's ID here!
	//not that $field_structure is not the same as field config, but that is stored in $field_structure[ 'field' ]
	if( 'fld_1234' == $field_structure[ 'field' ][ 'ID' ] ) {
		//IMPORTANT - for American-style dates use a "/" IE - m/d/y, for European style dates, use a "-" IE d-m-y for euro style dates, because PHP
		if( time() > strtotime( '02/11/2016' ) ){
			//For hidden fields use "value", for other types, use "default"
			$field_structure[ 'field_value' ] = 50;
		}
	}

	return $field_structure;


}, 10, 2 );

caldera_forms_render_field_structure-move-description.php

<?php
/**
Move field description (caption) above input, below label
**/
add_filter( 'caldera_forms_render_field_structure', function(  $field_structure, $form){
	//place description after label
	$field_structure[ 'label_after' ] .= $field_structure[ 'field_caption' ];

	//empty description so it doesn't show twice
	$field_structure[ 'field_caption' ] = '';
	return $field_structure;

}, 10, 2 );