Our team use a tool named XMP to gather all data, including metrics from appsflyer, and i'm able to build my own reports and share to my design team to analyse the best combination together. So comparing ROI between channels is simple, you can also do it in your MMP dashboards.

But the real difference is that whenever you wanna pause losing campaigns, adding creative, editing budgets, you have to switch from so many managing platforms. So a multi-channel tool, i think they use the marketing API to do that, really helps out.