Hi grey9hound. Yes, I’m sure that the Siemens are well broken in. Here’s what I wrote earlier in this thread: "...the matched Siemens e188cc were bought from Upscale Audio in 1997 and used for only a few months in a Sonic Frontiers SFS-80 amp before selling the amp and stashing the tubes...". Probably 300-500 hours of use in 1997...but probably another 400-600 hours in 2020-2021 in our Dodd Battery Powered preamp. So, yes, by any normal accounting, they’re well broken in.
Just something very special about the Voskhods.