undergo testing for conditions like Congenital Adrenal Hyperplasia or XXY?
No.
Chromosomal screening is not routinely done according to the recently released Australian guidelines.
The issue is whether there is a relationship between transgenderism and intersex conditions and no there is not. If a condition is not higher than the usual population, then there is no evidence to screen and perform investigations that are unlikely to produce any useful outcomes. Transgenderism seems to be an independent phenomenon and does not seem to have a relationship with intersex conditions according to current research.
Chromosomal analyses are rarely abnormal in TGD individuals and should only be performed if there is clinical suspicion (eg, Klinefelter syndrome). Genital examination is not routinely required.
References:
Cheung, A. S., Wynne, K., Erasmus, J., Murray, S., & Zajac, J. D. (2019). Position statement on the hormonal management of adult transgender and gender diverse individuals. The Medical Journal of Australia, 211(3), 127–133.