Sorry, but that 2nd idea essentially does away with LTIR, which no one wants. It's not a viable concept.
And the first absolutely does prevent healthy players from playing. It also creates a situation where a team expects a player back for the 2nd round, but is forced to put out a diminished roster in the first round to accommodate for that possibility. Let's leave Stone for a second and look at Filip Chytil. He was back skating with the team today after being out with a concussion since November. As far as it seems right now, it's still pretty unlikely that he's going to be available for the first round. They used some of his LTIR space to acquire Alex Wennberg and some of it, combined with Blake Wheeler's LTIR space, to acquire Jack Roslovic.
Your idea creates a situation where the Rangers would be considering activating Chytil from LTIR and keeping Wennberg or Roslovic off the roster, or keeping those latter two on the roster and saying that even if Chytil is healthy enough to play in round 2, he won't be able to. What mechanism would there be to even keep the acquisitions from playing? They aren't hurt, so you can't put them on any kind of IR.
No it doesn't. They would keep the roster as it was without being to use the LTIR player.
LTIR is meant to allow for teams to replace a player that they realistically don't expect to be back. Or if a player suffers a career ending injury, not to milk out an injury until the cap no longer applies.
There should never be a situation where, 11m player gets injured, but is going to come back for the PO, and the team then spends that 11m on players at the deadline and then starts crying but we wanted our 11m player for the PO too.
There doesn't need to be a mechanism outside of if you didn't activate the LTIR player for the last day, then he cannot dress for a game. there's no roster limits in the PO so it's not like they lose anything by having him move to regular IR on the last day of the season.
I don't generally have an issue with LTIR but Vegas has gotten brazen enough with it that it does need to be fixed.
If the NHL season is 100 days,
If the players is going to play in the PO, he needs to be on a cap compliant roster on the last business day of the season. moving him to regular IR doesn't use a roster spot so no issue there but waivers are still in effect so they can't just bury players to open space to dress him.
No games get scheduled on day 100, LTIR players get "activated" to regular IR. If they cannot be cap compliant on day 100 with the LTIR players activated, then the LTIR player can't play in the PO. players aren't paid for the PO so no money is lost by the player and If you're expecting a LTIR player back for the season, you shouldn't be using all of the LTIR pool on deadline pickups.
the 2nd idea doesn't do away with LTIR, it gives teams that lose a player a buffer (~2m) to replace a player, it doesn't give a team a 10m cap increase that can be dispersed across the roster, because again the idea of LTIR is to replace that player, not give the roster an entire face lift with it, which is what has been happening instead.
Yet another option is that LTIR open up salary to be spent on 1 player up to the players cap hit.
So in the case of Stone, they could add 1 player at up to 9.5m. but not add 2 players with a 4.5m cap hit. It would let them add Hertl but not Hanifin (or vice versa)
There's many options to fix it, teams like Vegas, Tampa and Chicago have milked it because they were fortunate enough to have an significant salaried player get injured around the deadline for about long enough to milk it to the PO when the cap no longer applies. Which would typically be a 1 off, but Vegas has just gotten so blatantly obvious with it at this point though that it needs to be addressed, you have healthy players sitting out game 80/81/82 because they wouldn't be cap compliant.... i mean they're "unhealthy" and somehow 100% healthy 2-3days later for the game 1 of the PO.