Custom multifield xtype from classic ui to touch-ui failed

HI,

We are using custom multifield  xtype in classic ui which stores as string array and now we are migrating to touch-ui in aem6.3.

I used dialog conversion tool to migrate and after conversion custom  multifield is not working.

here my query is in classic ui it was storing as string array but in touch-ui i tried multifield and observed it is storing as node.

In touch-ui(coral)  can we store custom multifield as string array like we were saving in classic-ui.

What should be taken care while migrating custom xtypes to touch-ui from classicui.

Thanks

Srinivasula Reddy