I'd expect a shorter stabilization period is needed with a transition like this, so you might get some useful information with testing at 2-3 weeks, even though 4 would be preferred. It will be useful to ensure you're not running lower than expected. I'd say it's common to have difficulties with a dose reduction; I know I've had transient problems with sexual function in these circumstances. It can feel like a return to hypogonadism, which prevents many from following through. It helps to expect it, and to know that a fair evaluation of a new protocol requires months, which takes patience.
