This has been said many times before.
Brexit supporters on the right who complain that the socialist utopianism of Corbyn etc isn't pragmatic are ridiculous.
You can't complain about utopianism while wanting the UK to jump off the Brexit cliff hoping there will be a soft landing.
Brexit is not a pragmatic project.
Labour's position is not much better. You can't claim your manifesto is fully costed if you don't cost out the economic impact of your policy of ending freedom of movement.