I'm not seeing anything about this via a search about this, so forgive me if this is a known issue.

Maul is not giving Darkswell. It's giving Dark Embrace instead. So no 15% DR after Maul. The 3% from Entropic Field is present. But no 15% from Darkswell. The extra 15% DR would definitely aid survivability.

It's actually there but you can't find anything about it back in the character panel.

If you want to test it for yourself get a sorc to dot you before and after mauling something.

Darkswell itself itself is not an active buff you'll see on your toolbar, it just changes the effect of Dark Embrace to also reduce damage taken by 15%, so whenever you get Dark Embrace including after using Maul you'll get that DR.

The character pane doesn't show a change in DR, whereas the Operative talent for Kolto Probe DR, for example, does show on the character panel--hence my confusion.

The character pane doesn't show a change in DR, whereas the Operative talent for Kolto Probe DR, for example, does show on the character panel--hence my confusion.

Yeah that's a common slip people have. There's a difference between Damage Reduction and Reduces Damage Taken - I.E Kolto probes for an Operative (with the utility) increases damage reduction additionally to the DR they already have, whereas Reduces Damage taken (Darkswell, Invincible for juggs, etc) is a multiplicative calculation separate from Damage Reduction.

Yeah that's a common slip people have. There's a difference between Damage Reduction and Reduces Damage Taken - I.E Kolto probes for an Operative (with the utility) increases damage reduction additionally to the DR they already have, whereas Reduces Damage taken (Darkswell, Invincible for juggs, etc) is a multiplicative calculation separate from Damage Reduction.

^Exactly this, it's the same reason why you won't see Jugg's Invincible on your character sheet, but you will see PT's Energy Shield on your character sheet.