It seems, that it was not the case. My instance was still running in the background, and successfully reached block number 11762, without your fixes (I guess JavaScript is not reloaded, as long as I won't press F5).

Also, as you can see, I have a minority fork with 11616 blocks. Which means, that there are two chains: one is made by the original network with 371.10 ZH/s, and another one is made only by me, with 7.00 MH/s. It is based on the same Genesis Block, as it was the case in the original Gavin's testnet, before it was changed.

My plan is to see, if the official network can halt. I also wonder, if your chain is compatible with BIP-42: https://github.com/bitcoin/bips/blob/master/bip-0042.mediawiki

Because in the original code, after 64 halvings, the network started again with 50 coins. It was fixed by BIP-42, and I wonder, how your network will behave after 64th halving, and even if it can reach it without halting.

Also, I think some kind of "save" button will be needed, sooner or later, because then, it would be easier to restore the state of the network. Another feature I think about is "pruning". Because currently, everything lives in a memory. And if I could save some blocks on disk, and detach it from RAM, then it could be possible to test thousands of blocks, without killing my browser. Or even: pruning alone, without saving things, is also an option, to test some edge cases, like "no new nodes can join, because nobody has the full history anymore, and everyone switched to pruning".

The current chainwork:
And some minor UI things: when the price per coin is around 2.7 million dollars, it is no longer fully visible in charts. Also, charts seems to be in the future, because I have transactions from Jan 5, while I can see Jan 7 on the exchange.