They dont go nuts with stitches anymore, the spin I got was that it is left open to let any infection out.
Had a good cut like that some time ago about 2 inches long from the base of my "pointer", finger that is, on the palm of my hand, went to work the next day, construction, the day after did a 600 k road ride and rode home the day after.
Worked the next week and pulled out the stitches on the fri, she healed great, can hardly see the scare.
Might be a bit risky doing MX but anything else should be ok.