Yes, repairing armour will take off a bit of the overall durability of the armour depending on which trader you use to repair. If i find a broken armour after killing someone like 0/60 can i take it out with me and repair it? I guess I just got Tarkov'd, anyways just an interesting little story. Turns out he would need a LOT of hits before he could even penetrate my armor with that ammo.
Few hours later I remembered it again and found it curious so I tried the Battle Buddy app with the penetration simulator. Well anyway, went into the injury screen and noticed that he got me into the thorax with 9x18 PM PS gs PPO armor, so I figured he killed me with a Makarov, I laughed it off and forgot about it. When he did we started shooting though he quickly put me down in what seemed to be at max 3 bullets. Anyways threw a nade from the office towards the area he was in to supress him and went out of room and waited for him to peek. I threw a nade and then tried to rush him but he escaped towards the stairs area (His running animation suggested he was carrying a pistol). Anyways, I got into the third floor office area, when suddenly there were shots going off at me, luckily he missed all of those.
I spawned in with SSh-68 helmet and MF-UNTAR armor vest which was at durability ranging from 37%-44% (can't remember which one exactly, though I'm leaning towards the 37%). I was trying to do that one quest for Jaeger where you have to kill 6 PMCs at the Factory office area.