Dual SIM - eSIM & DIGITS

I have an iPhone 13 and currently enrolled in the Go5G Plus plan with T-Mobile. I plan to upgrade to the iPhone 15 in the next week. 

I am paying for an additional DIGITS number/line ending in "2672" which costs $10/month. This addition I was told allows me to text/voice call with a separate number on my iPhone now. I have heard from a friend I do not need this additional line as I can just convert the number to an eSIM line and have dual SIM on my phone. I am a bit confused after researching this a little and seeking clarification.  

• I want to know if I can transfer the DIGITS number ending in 2672 (I am currently using the DIGITS number as my business #) to an eSIM line and eliminate the need to have DIGITS all together?
• Can I send and receive text messages/phone calls through the phone using both my personal number ending in 9777 (on the physical SIM) and transferring the DIGITS number “2672” to eSIM? 
• If the above is possible and I can keep the number ending in “2672” and convert it to eSIM, does that mean that I need to pay T-Mobile for activation of another voice line to use it or would that be included in with my postpaid Go5G Plus voice line that I am already paying for?

I need to be able to keep the “2672” number to send and receive calls/texts as that is what’s saved in my clients/doctors address books and what I have marketed/advertised for my small business. 

Thank you in advance for any help & insight.