How to run 3 external monitors plus laptop monitor Dell 5530 + TB16

I speculate Dell is NOT including the laptop display in their count since they specify only 3 external (display) ports. So your model could only support laptop LCD & 2 external monitors or close lid & possibly 3 external monitors

This tech page notes 3 displays, not what type which is the point of contention. At the very least its another resource to checking wording against. Dell may be the only person who can confirm this since the wording can be open to interpretation.

--EDIT: pg34 of dock manual SEEMS to confirm: If three monitors are connected to the docking station, then the docking station will only support a maximum of two external monitors. Refer to the User Guide of your docking station for information on how to select and activate the desired monitors.