If TRT is working, the PHTA is shut down. In that situation I would not expect to see any difference with the time of day.
If on HCG, best taken as 250iu SC EOD. The T level changes will be very low. Testing is probably best 1/2 way between HCG injections. With the T production of the testes controlled by the HCG, I would not expect that AM vs PM testing would be an issue at all. And for weekly or longer injection cycles, EOD HCG would create a T level floor [assuming that the testes are still HCG/LH responsive] higher than zero.
Twice a month will leave one with very low T. E will be elevated and SHBG increased. As the T levels fall, the free testosterone will then have effects diminished by the E and SHBG.
Testing after two weeks will show a meaningless number... lowest of the injection cycle. Testing just before or after injecting will have little effect as the release of T esters and conversion of T esters to T takes time.
Most of the time, the best time to do T testing is 1/2 way through the injection cycle. But that is probably not good on a two week cycle. Probably need to inject once a week at least to get decent level control and testing.