How many E-SIM can I have active on my phone without a physical SIM installed? Can the phone run without the sim tray inserted?

PART 2: how does an IMIE number relate to a SIM card? I thought the IMIE attached to a device and not a SIM card. Only after installing a SIM card will the IMEI be attached to the device.

Can help clarify for me please.

[Re-Titled by Moderator]

Original Title: SIM / ESIM / IMEI / IMEI2