You may want to take a look how Bitrix24 approaches helpdesk, even though they are free - https://www.bitrix24.com/tools/contact_center/ . The idea behind Front or Helpwise (and it looks like you are inspired by them) is that the biggest problem is routing requests between different people and collecting requests from all available channels in one place. The idea behind Bitrix24 is that 'single inbox' and 'multichannel' is just the beginning. Your helpdesk has to be a part of your communication and marketing machine. Intercom.io is having a similar approach. I believe it's more promising.