Is is possible to use Templates with blockprops?

There’s a part in the documentation which says: (bold and italic formatting added by me)

The useInnerBlocksProps is exported from the
@wordpress/block-editor package same as the InnerBlocks component
itself and supports everything the component does.

So yes, you can set a template via useInnerBlocksProps, using the second parameter like so:

const innerBlocksProps = useInnerBlocksProps( blockProps, {
    template: [
        [ 'core/paragraph', { placeholder: 'Summary' } ],
        // other templates
    // other properties