This is more complicated a question than you may realize
It's dictated by a few factors.
Maille sleeves start showing up in inventories around 1325 as a separate piece of kit from a haubergeon (a shorter hauberk). Maille sleeves would be worn in conjunction with paunces (or a maille skirt). So the option existed from around the second quarter of the 14th century. So which would you wear? Well, it probably depended on what else you were wearing, specifically your torso protection.
If you had no other torso protection, then you would want to wear a full mail shirt, not separate sleeves obviously.
If you had limited torso protection or only protection for the front, you would still want to wear a full mail shirt. In my kit for example, I have a breastplate with fauld but not backplate. I do an impression of a gentleman of 1380 - 1415 depending on the scenario of the re-enactment. I still wear a full haubergeon under all of my plate because otherwise my back would be undefended.
If you have a full torso protection in either the form of a breast and backplate, or a coat of plates that features plates in the back specifically, then you might just wear sleeves instead since the mail would then become redundant. Even then you may still opt to wear a full shirt underneath.
For me personally, until I make a shift to getting a full cuirass I would not swap out my haubergeon for sleeves and paunces. The reasoning is that a well-equipped man-at-arms should be striving to leave no part of his person unprotected within reason. So you wouldn't intentionally leave a place that's not defended by either maille, plate, or both if you could help it. So there's no reason to wear anything less than a hauberk if the rest of your harness doesn't already cover the same portions of your body.
By the 15th century when plate was relatively fully developed in coverage, then sleeves or voiders would be the norm. However, even then we still have evidence for full shirts of maille being worn beneath plate.
Oh and as far as pointing, if your maille is properly fitted to you armor will point directly to it just fine. I point my arms directly to my haubergeon and it's no problem.