If you disable the PublishPress Blocks plugin, the blocks will revert to HTML. This means that PublishPress Blocks is a safe option to use, because your content is not locked into our plugin forever.
Here is an example of our Columns block, after the plugin was disabled.
If you click on the “Keep as HTML” button, you will see that the block uses normal HTML code. You can add your own CSS styles to your theme and keep on using this block.
Here's another example using the Images Slider block:
And here is the HTML code for that same Images Slider block: