Sneak would be serviceable with this small tweak.

Sneak ,as it's been program ,would be an okay skill if the world was perfectly flat.
It only takes your target to be on a hill and they counter your meele assassination. This makes most players abandon it because of its slow pace gameplay and grueling flaws of the terrain moment while stealthed.

My solution would be adding crouch-running and crouch-jumping

Crouch-running:
The purpose of this addition would to introduce the unique property of hill-running that valhiem currently has,while maintaining your silence/stealth.

The speed of crouch-running would be walking speed, always. Which would be a nice improvement to speed things up a bit.

It would not only train both skills at their own rate default rate but it would also combine both thier respective SCR's (stamina-consumption-rate)based on thier levels. For example,if my SCR for sneak is 10 per sec and running is 8 per sec, it would consume 18 per sec while using this method.

The way to activate this would be, sprinting while crouch is on.

Crouch-jumping:
When you jump while crouching you maintain your crouch position in the air , maintaining your silence/stealth, to help in situations that you need to get over objects like logs and barriers.

Just like the previous example, it would use the stamina of your jump normally would. Movement while In the air would use your stealth's SCR.

In summary,
it's just stacking running and jumping while in the crouch state, the draw back would simply be high stamina usage to sneak around more effectively. It would be a good implementation to bring it up to a baseline like the other movement skills,because right now it's subpar.

Do you guys think this is a bit much,or what would you change with stealth if anything at all.