Jh is guaranteed through life expectancy so at that age, probably late 70s. It is a true LTC rider (7702b).

so at age 80 she'll either have a huge increase in premium OR she'll have to cut her benefits big time or she'll lapse the policy and lose everything. why would anyone want to buy a policy like that?

You asked guaranteed. That would assume that they max COIs and reduce the interest rate to the min the day she buys it. Non-guaranteed goes 125ish... The outcome is likely in the middle. The JH policy looks a lot better overfunded... but then you're in ACIV premium territory anyway. BTW, I agree that for a couple, ACIV is a better solution if LTC is your primary objective (and you want a hybrid).

It would be so much easier to really compare these plans with 2 illustrations and have all the numbers.

It's a current assumption UL. $4600 annual premium is too low to carry the policy. At age 87, internal rate of return on a $4600 premium for $1,000,000 db is 9.03%. Policy funding will need to be much higher. Need $11000 year premium at 5% IRR to fund $1,000,000 DB at age 87. Pay now or pay much more later.