Hi Vic
Yep, i think the Thief series had a crystal mechanic where by looking at the crystal showed the level of light you a standing in.
Not that we expect that mechanic.. as long as its fun.. at times useful.. but not game breaking.
If in most fights you can't hide, shoot, hide, then enemies take no action.. then you shoot, hide....repeat.. not fun.
But if your friendly half-orc barbarian is beating the enemy senseless... and theres no reason why the enemy should target your hiding halfling gloom stalker ranger in darkness.. then hiding should work. In fact if you know you arent going to be targeted because the enemy is busy you don't really need to hide!
But fighting solo against a spellcaster.. expect them to try to find you.. AOE.. cast find hidden... cast see in darkness.. go invisible themselves, call for backup, run away etc