I played with the TMS1100 rev E from Lost Treasure, seeing if I could get it to dump all 8 bits. Most of the dumping process has the reset line asserted, but you have to release it for a few clocks to get the data to dump. I changed the timing of when reset is released, and was able to get all 8 bits to dump. But when I tried it on other Rev E dies, it didn't work. The Lost Treasure MCU is a 28 SDIP marked DES, and I don't have any others marked the same to test. I decapped it and I'll confirm that the 8-bit dump I got was correct.
I still haven't had any luck dumping the O output PLAs from TMS1000s or Rev E 1100s. I'm not sure why it's not working.