I tried to squeeze 1 more trip out of my deteriorating trailer king (china bomb) tires this past October & got a blowout on I65. The tires were about 4 yrs old with 12k miles but had uneven wear on edges. Dw was upset, not only because she had to assist changing the tire on I65 while getting chewed up by fireants, but I later fessed up to her that I was aware of the china bomb problem & tried to squeeze 1 final trip before snow started falling & then replace the tires this spring.
So my advice to you is if you do try to squeeze more trips out of questionable tires, & you do suffer a blowout, then don't tell DW that you were aware of these issues. Better to show her beforehand some of these many china bomb posts, & my guess is she will be demanding new tires asap. :)
This weekend just got some new goodyear endurance tires(5 of them); she insisted on 5 even tho the aging trailer king spare had only a few hundred miles on it. Hope the endurance will hold up better. We will see.