Yes I can compare mint to apex, Different PoS Parameter do affect security, but PoS is still PoS,
your current parameters will only work well with a PoS 1 style coin, as not everyone can keep a system online 20 days straight, that is why min stake age would have to be lowered with a PoS II coin.
The only point I am stating is if there is a switch to PoS II, it will require a change in min stake time, no way around it. When you get a new dev , he will say the same thing, if you want your users to be able to stake a PoS II style coin. If you don't switch to PoS II , then parameters change is not an issue, only if you do switch.
PoS security is determined by the # of coins staking and their weight.
Currently 3% staking at the time of this post, comes out to 635,5557,506 mintcoins.
51% attack
635,557,506*51%= 324,134,328.06
if someone waited until max weight is achieved 20X
324,134,328.06 /20 = 16,206,716.403
Then for only ~16,206,716.403 mintcoins purchased , someone could doublespend on your network after reaching full weight.
FYI:
Your Max weight is 20 days not 40 days, weight does not begin until 20 days and it stops gaining weight at 40 days. So only 20X the amount per block is the max weight, not 40x.
I would agree with this, as one who opened both my Mint & Zeit wallets over 6 months later to stake (I would almost call them twins, if you look close enough at the specs). I only had a very small amount though, still remember Ray's face palm of my post & it should be a must to be able to open any one of these apps up months/years or even decades if there is desire to (otherwise why is this being created, to always trade 100% of holdings & not hand down to future generations or save up for school/car/house/etc..)? I try to look past the flaws, since I know they will be worked out in the future & just hope that future is close enough this realm of time we stand in