So, again: chain-hopping has been known to cause what Terracoin and Feathercoin stupidly suffered, which is why almost all coins put in fixes years ago so they would not suffer like Terracoin and Feathercoin recently did.
Do you know any other coin except TRC that can do this:
2013-05-09 20:02:41 RETARGET: artificially lowered diff ; hard time mining current block...
2013-05-09 20:02:41 Before: 1b015a79 0000000000015a79000000000000000000000000000000000000000000000000
2013-05-09 20:02:41 After: 1b02b4f2 000000000002b4f2000000000000000000000000000000000000000000000000
I don't.
I'm not sure where you found that FTC has fixed any of the known issues. From what I know, it is mere copy and paste of LTC with few minor changes.
Could you explain time-travel attack a bit more?
From the little I have seen so far about TRC's "solution" it sounded like it planned to try to refer to clocks / timeservers, which is a huge can of worms that Bitcoin goes to a whole lot of trouble to work-around.
I0coin still dies regularly trying to do a DNS lookup to find an IP of a network time server, so the idea of trying to find out the time does not sound like a good idea at all.
The solutions other chains have been using seem to work well, so why go out of one's way to add another point of failure by imagining a timeserver might exist somewhere and that one might be able to find an IP number that it can be contacted at? Especially after I0Coin seems to have already demonstrated that that can be a cause of crashing of the daemon?
I only know though that the fix DVC and GRP and I don't recall which other chains used has seemed to actually work in the field, whatever alternative other chains used I am not sure has even yet been tested, as in, actually been through a major chain-hopping and shown that it is indeed resilient in recovering from hopping.
So I do hope whatever TRC did end up doing isn't opening the whole can of worms of trying to figure out what the actual clock/calendar time out in the world might be because so much work already went into making that not be something that nodes need to rely upon the accuracy of.
Basically the timestamps on blocks can be way out, but overall between the lot of them do give at least a vague general idea of approximately how much time might have passed in the real world, and depending on knowing more than what can be gleaned from those timestamps is a bit of a hairy mess, best avoided.
-MarkM-