The Cricut fine point blade which is used for 95% of vinyl cutting is spring loaded and after market ones are easily available Explore Deep Cut Blade with Housing Compatible with Cricut Maker, Maker 3, Air 3, Air 2, Air, One, Explore 3（2 Blades) Black : Amazon.co.uk: Home & Kitchen
I am sure it would be fairly easy to make a holder with a 3d printer or scratch built from mdf or plastic.
It may be worth purchasing a cricut mat to hold the vinyl while being cut
Good Luck