Don't do this. I strongly believe this is wrong. This way we will never know the real market value of the coin until the wallet opens! And what do you think miners will do, if they cannot dump the coins on market immediately while mining?
In that case they will either
a) don't mine at all (which will drop the hashrate, and hence the mining price of the coin);
b) or keep their coins until the wallet opens, then dump all them immediately after wallet opening, killing the price of coin. As soon as buy wall is removed at that point, ICO investors will be screwed then - left with bags full of coins they cannot even sell back at cost!
Both things are bad for the coin, so please refrain from doing this. I would be interested on what community thinks about this though.
I completely disagree. The point of the post-ICO buy wall is to allow ICO investors to sell back their coins if they decide they regret having bought into the ICO (unlikely to happen IMO since this coin will be dramatically undervalued at the ICO price), the post-ICO buy wall is not supposed to be there for miners to dump into. If you are going to let miners dump into the post-ICO buy wall, just don't have a post-ICO buy wall because that completely defeats the purpose.
Well, let me explain once more.
If the buy wall is set only when the wallet is closed, nothing will happen during those 5 days, nobody will actually sell/buy a lot, and things will be very quiet until those 5 days pass. ICO holders will have no reason to regret and sell coins back, because the REAL value (determined by real world, including the miners) will not be clear. No new info, no action.
Then 5 days pass, the wallet opens, buy wall disappears, and real world (and miners) intrudes into the scene! Price may fall immediately, and poor ICO investors cannot do anything anymore. Even if they want to sell back, they cannot, because the buy wall is gone!
This situation is good only for scamcoin developer (I am not telling this one is!), to be able to get the funds out, before the real market stabilizes. And this approach in reality defeats the purpose of buy wall!! Because buy wall will be there when nobody needs that, and will be gone when it is most needed.
Hope I explained my point better. I would personally never invest in ICO if wallet will be closed. I will buy from miners huge dump when wallet opens