Echoing what Prodigy said--don't use the UI module except for creating new blank layouts.
Save your map/mod as .sc2components and edit your layouts with notepad++, because animations and stategroups fail to compile in the UI editor.
There's no need for the editor UI previewer (which doesn't really work to begin with) between the in-game UI editor (CTL+ALT+F12) and UI reloading (CTRL+ALT+F11), which lets you update your UI (edit in notepad++ and save) without relaunching SC2 through the editor.
This is the public release of PiratedFloatingText which you can download here or from my assets page.
This mod uses layouts to create smooth animated combat text similar to the combat text found in Heroes of the Storm. Style and directionality options are included for customization. Text styles included as follows: Basic, Basic Crit, Ability, Ability Crit, Healing, Healing Crit, and Status. Crit variants have slightly longer airtime and include a highlighting icon (except for Healing Crit).
Middle (Ability Crit)
Right (Healing Crit)
I hope you find this useful. The layouts are relatively easy to customize for you own purposes.
I believe the InventoryContainer frames (ContainerPanel00, ContainerPanel01, etc) are hardcoded to scale with Top Left and Bottom Right inventory slots (00 and 10) at map initialization, and thus before your triggers are run.
InventoryContainer dimensions can be manipulate by changing the size of these two slots in a new layout file (and possibly their offsets? I don't quite remember)