Something like:
// #popclip
// name: S p a c e d w o r d s
// icon: sw
// language: javascript
// after: paste-result
let result = "";
for (const c of popclip.input.text) {
result += " " + c;
}
return result.trim();
(The above block is an extension snippet — select it then click “Install Extension” in PopClip.)
Note inserting the spaces will mess up with some emoji, e.g. 
becomes 
and 
becomes 🇦 🇺 .