Hi. Let's see an example.
<textarea class="Magento\Ui\Component\Form\Element\Textarea"> <argument name="data" xsi:type="array"> <item name="js_config" xsi:type="array"> <item name="component" xsi:type="string">Magento_Ui/js/form/element/textarea</item> <item name="config" xsi:type="array"> <item name="template" xsi:type="string">ui/form/field</item> <item name="elementTmpl" xsi:type="string">ui/form/element/textarea</item> </item> </item> </argument> </textarea>

Is it real to change that path
<item name="elementTmpl" xsi:type="string">ui/form/element/textarea</item>
in this way
<item name="elementTmpl" xsi:type="string">MyModule/form/element/custom_textarea</item>

Thx.