How to remove extra spaces from Field Values when using webmerge?

I have done lots of WebMerge buttons/data exports over the past year and really enjoy its functionality.  I'm having a new issue though with using checkboxes for the first time. I noticed they are not triggering in the PDFs I'm shooting the data to in WebMerge because I first have to strip the tags but it leaves a space in front and behind the Yes value.  

Example {$checkbox1|strip_tags} leaves a raw value of " Yes "  (notice the spaces there).  This will not work with Acrobat.  Any ideas on how to get rid of that space?  If I don't do the Strip_tags, it has all kinds of html data/span ID/etc that is shot over from Knack.   Surely there's a better way to do this either in the javacscript code in Knack, or in Webmerge or in Acrobat??   Example code in Knack here:

// WEBMERGE FOR VA RFS
$(document).on('knack-scene-render.scene_43', function(event, scene) {

$('#view_75 .view-header').after('<div style="padding:16px"><a href="#" id="webmerge" class="kn-button">Generate VA RFS</a></div>');
 
// link hander: send to webmerge
$('#webmerge').click(function(event) {
event.preventDefault();

// get data
var data =Knack.models['view_75'].toJSON();
var record_id = data.id;
  
log('data!');log(data);
Knack.showSpinner();

$.ajax({
  url: 'https://www.webmerge.me/merge/705551/4hk38d',
   data: {
     patientname: data.field_337,
patientaddress: data.field_35,
patientphone: data.field_37,
checkbox1: data.field_23,
record_id,
   },
   type: 'POST',
   success: function() {
alert('Document Created!');
   Knack.hideSpinner();
   },
error: function() {
alert('There was an error creating the contract, you suck!');
}
});
});
});
 
Thanks!
JD