Advice on keeping Berserker Axe fun?

If the name Thuradim Breakbones means anything to you, stop reading now! 🙈

I'm a first time DM running LMoP for a mix of old and new players. We play short sessions every couple of weeks, so I wanted to introduce fun magic items early in the campaign. As such, our level 2 fighter picked up a Berserker Axe at Cragmaw Hideout. However, he hasn't yet discovered that it's cursed:

Whenever a hostile creature damages you while the axe is in your possession, you must succeed on a DC 15 Wisdom saving throw or go berserk. While berserk, you must use your action each round to attack the creature nearest to you with the axe. If you can make extra attacks as part of the Attack action, you use those extra attacks, moving to attack the next nearest creature after you fell your current target. If you have multiple possible targets, you attack one at random. You are berserk until you start your turn with no creatures within 60 feet of you that you can see or hear.

What I'm realizing is that he may not take damage and learn about the curse for the first time until they head into Tresendar Manor, where it will be impossible for the party to get 60 feet away from him without splitting into different rooms, or even fleeing the manor.

As I've read other posts about this item, there seems to be a consensus that it can be unfun, since it takes away player agency during combat. Between these two issues, I'm wondering if I should introduce some changes to the berserk status.

A few ideas I'm toying with:

• Once the party realizes the axe is cursed, I'd like for them to be able to get help from Sister Garaele. It could be part of her quest reward that she can either (a) help the fighter unattune the axe, or (b) help the fighter gain some resistance to the axe's curse (lowering the saving throw DC, for example). However, I don't want this to be a blocker for dealing with the Redbrands.
• In the meantime, I was thinking about allowing the following:
  • Once berserk, allow fighter to reroll the Wisdom saving throw if he is somehow prevented from using his action to attack on his turn (for example, if the party grapples him).
  • Allow other party members to use their action to roll Persuasion to snap him out of the berserk status.

Any suggestions? Alternatively, if the item is actually fine the way it is, any tips on how to run encounters in a fun way while it's in their possession? Thanks!