class Form extends \Magento\Backend\App\Action
{
    public function execute()
    {
      .....
        $block = $layout->createBlock(\MageSuite\CmsDuplicate\Block\Adminhtml\Duplicate\Form::class)
            ->toHtml();
        .....
        $resultRaw->setContents($block);

        return $resultRaw;
    }
}

<?php
/** @var \MageSuite\CmsDuplicate\Block\Adminhtml\Duplicate\Form $block */
$page = $block->getPage();
?>
<div id="duplicate-page-modal">
    <form method="post"
          id="duplicate-cms-page-form"
          action="<?php echo $block->getUrl('cmspageduplicate/duplicate/duplicate') ?>">
          ...........
          
          <?php $blocks = $block->getBlocksToDuplicate(); ?>          

class Form extends \Magento\Backend\Block\Template
{
    protected $_template = 'MageSuite_CmsDuplicate::form.phtml';
    
    public function getPage()
    {
        if (!$this->cmsPage) {
            $pageId = $this->getRequest()->get('page_id');

            $this->cmsPage = $this->pageRepository->getById($pageId);
        }

        return $this->cmsPage;
    }
    
    public function getBlocksToDuplicate()
    {
        $page = $this->getPage();
        $layoutXml = $page->getLayoutUpdateXml();
        $components = $this->xmlToComponentConfigurationMapper->map($layoutXml);
        
        $blocks = [];
        foreach ($components as $component) {
            .....
            $blockData = $this->getBlockData($component);

            $blocks[] = $blockData;
        }

        return $blocks;
    }
}

class Duplicate extends \Magento\Backend\App\Action
{
    public function execute()
    {
        $data = $this->getRequest()->getPostValue();

        /** @var \Magento\Framework\Controller\Result\Json $result */
        $result = $this->resultJsonFactory->create();

        if ($data) {
            try {
                $newPage = $this->pageDuplicator->duplicate($data['page_id'], $data['title'], $data['identifier'], $blockData);       
            }
            ......
        }

        return $result;
    }
}

class PageDuplicator
{
    public function duplicate($oldPageId, $newTitle, $newIdentifier, $blocksData = [])
    {
        $oldPage = $this->pageRepository->getById($oldPageId);

        $duplicatedPage = clone $oldPage;
        .....
        if (!empty($blocksData)) {
            $duplicatedBlocks = $this->duplicateBlocks($blocksData);

            $this->assignDuplicatedBlocksToComponents($duplicatedBlocks, $duplicatedPage);
        }

        $duplicatedPage->save();

        return $duplicatedPage;
    }
    
    protected function duplicateBlocks(array $blocks)
    {
        $this->validateIfNewBlocksIdentifiersDoesNotExist($blocks);

        foreach ($blocks as &$block) {
            $blockEntity = $this->blockRepository->getById($block['blockId']);

            $blockEntity->setId(null);
            $blockEntity->setIdentifier($block['blockIdentifier']);
            $blockEntity->setTitle($block['blockTitle']);

            $blockEntity->save();

            $block['newBlockId'] = $blockEntity->getId();
        }

        return $blocks;
    }
    
    protected function assignDuplicatedBlocksToComponents($duplicatedBlocks, $oldPage)
    {
        $oldLayoutUpdateXml = $oldPage->getLayoutUpdateXml();

        $oldComponentsConfiguration = $this->xmlToComponentConfigurationMapper->map($oldLayoutUpdateXml);

        foreach ($duplicatedBlocks as $newBlock) {
            foreach ($oldComponentsConfiguration as &$component) {
                if ($component['id'] != $newBlock['componentIdentifier']) {
                    continue;
                }

                $component = $this->mapNewBlockDataToComponent($newBlock, $component);
            }
        }

        $newLayoutUpdateXml = $this->componentConfigurationToXmlMapper->map($oldComponentsConfiguration, $oldLayoutUpdateXml);

        $oldPage->setLayoutUpdateXml($newLayoutUpdateXml);
    }
}

class ComponentConfigurationToXmlMapper
{
    /**
     * Maps components configuration to corresponding XML Layout format
     */
    public function map($components, $existingXml = '')
    {
        .....
    }
}