One item to consider (and plan) carefully is the velocity of depletion of HSA funds, especially for larger balances (say north of 50k or 75k).
Why ?
Because if the HSA is left to non-spouse heir(s), it becomes immediately a tax event for them, with RMD enforcement.
Why is that potentially a big deal ?
If you are over 59.5 and do not have a foreseeable medical way to spend the money and you die, it may be a better strategy to start spending the money and treat it like an IRA, perhaps converting some to Roth IRA. The alternative, with a possible tax bomb to your children may upset their financial plan. At least have a clear discussion and explain to them what may occur.