The real problem with trying to find a longer term deal is that if you want to take non-tendering him off the table, he is essentially guaranteed 2 years x 6.375MM at worst.
The team could take him to team-elected arbitration and have his salary reduced up to 15% (best case scenario: 6.375MM).
Now here's the problem: in team-elected arbitration the player gets to choose whether the award is 1 or 2 years. So, if he chooses 1 year, it's 1 year of 6.375MM, and then we have to again hand him a 6.375MM QO that walks him to UFA status. If he chooses two years, at best it's 2 years at 6.375MM and then he becomes a UFA.
The arbitrator could also award something greater than 6.375MM, and if that happens I guarantee you Boeser's camp takes the 2 year award all day if that happens.
To get back to negotiating with Boeser on lets say even a 3 or 4 year deal, if you're offering less than 6.375MM on those first two years, why should they accept that deal? Maybe if you're offering the long-term security, but that's probably the kind of deal we should be offering him at this stage.