Low Vars:
{if '{exp:low_variables:single var="test_var"}'} form: {test_var}: {exp:freeform_next:render form='{exp:low_variables:single var="test_var" parse="inward"}' parse='inward'} {/if}

{exp:channel:entries limit="1"} Field:
{if freeform_chooser_test} form: {freeform_chooser_test}: {exp:freeform_next:render form="{freeform_chooser_test}"} {/if}

Grid:
{grid_test} {if grid_test:freeform_chooser_test} form: {grid_test:freeform_chooser_test}: {exp:freeform_next:render form="{grid_test:freeform_chooser_test}"} {/if} {/grid_test}

Fluid:
{test_fluid} {test_fluid:freeform_chooser_test} {if content} form: {content}: {exp:freeform_next:render form="{content}"} {/if} {/test_fluid:freeform_chooser_test} {/test_fluid}

Blocks:
{test_blocks} {test_block} {if test_chooser} form: {test_chooser}: {exp:freeform_next:render form="{test_chooser}"} {/if} {/test_block} {/test_blocks} {/exp:channel:entries}