in circuit is a first general test / basic values check tests / when having doubts, isolate or remove the part
for sure there is some limits, and surrounding parts may play tricks on you
an open and close calibration when available is a plus,
ex: i use an de-5000 at my job, and each time i power it up, i do the open and close calibrations, and for sure, just moving the leads change values quite a bit .... human body presence ...
i use some circuits while putting rf in it, just being around it, play tricks loll i can not use any serial or parallel tests, it will self oscillate the circuit
but with experience and many many archived tests, even with an ohmmeter now i know if a portion is defective ...
The ET430 and up lcr meters are resold in many colors and brands, not sure for their quality

seems to have some decent circuitry

Tonghui have some protables ones too, pricing seems high
Hioki
Applent / and rebranded ones
old BK Precision models like BK885 BK886
now we beggin to have ideas ...