It's like I said in my earlier posts, the traceroutes look fine and because of the low priority nature that most network devices place on the ICMP protocol, the latency on specific hops don't mean much..
There is no doubt that they are running their international links hot.. from 18:00 to about 00:00 every evening, most people with internet start streaming, gaming etc.. Internet usage peaks and any ISP who doesn't have enough capacity to handle this increased traffic will result in their end users seeing packet loss and slow speeds, but not necessarily higher latency..
Packet captures and TCP based traceroutes may show any issues better, but at the same time, 1st line support for any ISP will just do the scripted troubleshooting procedure and they are unlikely to escalate your test results anywhere.. The unfortunate thing is, any good ISP will monitor their links and they will know that they are running them hot, but they will wait to the bitter, bitter end before upgrading those links, because it's expensive, the ISP market is competitive and eats at their profits..