I think you're misunderstanding. I'm not saying T-Mobile locks the EID and IMEI together. I'm saying their tech support will completely ignore any EID you send them and instead look up an EID in their database based on the IMEI you send them. If you manage to convince the tech support to actually listen to you and use the correct EID then yes, everything will work out fine and you'll be able to move the card across devices.
I was also using a removable esim (from jmp.chat) and they did this to me three times. Each time it went like this:
> Me: Please send me a QR code to download my esim. My EID is XXXXXXXX
> Them: Thanks for providing your EID, please send me your IMEI (the first time this was just a plain message, the 2nd and 3rd time they sent me a link to a form to submit my IMEI to them)
> Me: <sends them my IMEI>
<at this point, the first two representatives initiated a transfer through their app and told me to wait 2 hours and then the transfer would finish. I told them whatever automatic transfer they just initiated will not work and they _need_ to send me the QR code.>
> Them: What is your e-mail address
> Me: My e-mail address is XXXXX@XXXX.XXXX
and then they'd send me a QR code. I'd then attempt to download it to my jmp.chat esim and I'd get an error that the EID was incorrect. Then, I'd try using the QR code to activate the built-in eSIM on the phone with the IMEI that I sent them, and it would work, proving that they were looking up the EID for the IMEI that I sent them rather than paying attention to the EID that I started the chat with.
The 4th and final time, I sent them my Librem 5's IMEI which had never been on T-Mobile and does not support eSIM. They told me that the phone was carrier locked, I assured them it wasn't and explicitly told them "it is important the QR code is for the EID I provided you. The past representatives have ignored that, leading to the error message <pasted the error from EasyLPAC's logs that was something like EID is incorrect>". THAT time they finally listened and sent a QR code for the correct EID, which let me download the eSIM to my jmp.chat card. At that point I was able to move the card across devices without issue.
Apologies on getting back late but… I’ve never had that experience. Historically I would call during day and get someone stateside. They would ask for IMEI and I would say ‘it’s not in your db but EID works’ and then they’d let me read that off, never an issue. Now I use the chat, it’s faster since they just give a portal link you drop the details to.
Call during day or you get the Philippines and they don’t understand specific requests like this as well. If you must do it at night use the chat route.
I was also using a removable esim (from jmp.chat) and they did this to me three times. Each time it went like this:
> Me: Please send me a QR code to download my esim. My EID is XXXXXXXX
> Them: Thanks for providing your EID, please send me your IMEI (the first time this was just a plain message, the 2nd and 3rd time they sent me a link to a form to submit my IMEI to them)
> Me: <sends them my IMEI>
<at this point, the first two representatives initiated a transfer through their app and told me to wait 2 hours and then the transfer would finish. I told them whatever automatic transfer they just initiated will not work and they _need_ to send me the QR code.>
> Them: What is your e-mail address
> Me: My e-mail address is XXXXX@XXXX.XXXX
and then they'd send me a QR code. I'd then attempt to download it to my jmp.chat esim and I'd get an error that the EID was incorrect. Then, I'd try using the QR code to activate the built-in eSIM on the phone with the IMEI that I sent them, and it would work, proving that they were looking up the EID for the IMEI that I sent them rather than paying attention to the EID that I started the chat with.
The 4th and final time, I sent them my Librem 5's IMEI which had never been on T-Mobile and does not support eSIM. They told me that the phone was carrier locked, I assured them it wasn't and explicitly told them "it is important the QR code is for the EID I provided you. The past representatives have ignored that, leading to the error message <pasted the error from EasyLPAC's logs that was something like EID is incorrect>". THAT time they finally listened and sent a QR code for the correct EID, which let me download the eSIM to my jmp.chat card. At that point I was able to move the card across devices without issue.