Quote from: NotATether on Today at 07:15:14 AM

You don't need a lot of testnet coins to test stuff but you do need enough to cover the fees for long enough that the tests can run for several thousand iterations. So we are looking at around 0.1 to 1 tBTC for each project.

I honestly never understood this and I've seen so many of those who ask for high amounts of tbtc say it. What are these tests that need to run "several thousands" times in a live network that can not be abstracted away using IoC design or something like that or even run in Regtest instead.

Quote from: vjudeu on Today at 08:15:51 AM

And also, there is some risk of replaying coinbase transactions between networks. Which means, that if you have some block 1,234,567 in the current testnet3, then you can migrate exactly the same coinbase transaction into testnet4.

But coinbase tx is just a tx. There is nothing special about it in this context ("replaying" between networks). You set the version and the outputs of that tx and you get the same exact tx.

Quote from: vjudeu on Today at 08:15:51 AM

Which means, that blocks from testnet3 can be copy-pasted into other networks, but not the other way around, because it would require a huge chain reorganization in testnet3.

No you can't. Because the difficulty is different and also any block in any network is positioned inside a chain. You can't take out a single block from the middle of that chain and place it on top of another chain.
For example block 1,234,567 in Testnet3 is referencing block 1,234,566 on Testnet3 if you take that and try to place it on top of for example Mainnet chain at 1,234,567 it is rejected because the 1,234,566 reference is not found.
This chain also goes back all the way to a hardcoded Genesis block that is unique to that specific chain to prevent exactly what you explained.