Balance Core, drop in mode, speed fusion questions

Hi all!
I have the balance 20 and upgrading to balance core for greater throughput now that my primary internet bandwidth is higher. But I still question reliability and I have an 4g modem on the roof connected as WAN 2. I know I can set up outbound rules to minimum to reduce any time between a failover switch. Then I read about Speedfusion and I’m not sure I understand how the data caps and speed work. The data is only the amount of data that actively needs to be managed via speedfusion? And I’m limited to 100mbps bandwidth? Will the free trial give me tools to see how much I’m using? Finally, if I install everything via drop in mode and purchase speedfusion, am I correct to assume that no IP address switching should occur so that if I’m connected to my corporate VPN (or watching Netflix)I won’t get kicked off?

Thanks. Im happy to elaborate on anything.