Dual Sim // E-Sim - How does it work?

Hello this is more of a sales related question than tech support. I don't see enough articles out there on Google explaining exactly how dual sim works just announcements and such.

I am aware that using dual sim I can get a personal number and a business number..

My question is..

But can I control the business number "office hours" and not receive calls after a certain time of day or day of the week? (All this while keeping my personal line remaining open for such calls?).

Can the business line be set up with its own voicemail in my voice?

I am aware that I can make outgoing calls from my business line which is cool. I just have to remember to do that. Is there a separate app (with phone icon) for the business line in the phone Os?

I know these are very basic questions.. Currently I am a freelancer.. and I use Google Voice but it isn't perfect.. I have switched companies in the past few years...just feel like I'm missing out on some things like ability to set up separate business number for multiple entities. I actually work for 2 companies.

Thanks for any help you can provide.

My current phone is an iPhone 6s... upgrading is in the future. I guess if I decide to go dual sim ill get the iPhone 11. just hoping that it will also have dual sim.. (it should) can't imagine that Apple would create it then take it away.