Yea! Your FW410
, in addition to be a mixer, is a patchbay so you can, roughly, mix and direct what you want where you want. Cool, huh? All that controled with a software. What's asking furthermore?
Just link the UB802 main output to the FW410
line input. You can do it mono or stereo. If you do mono, just don't forget to pan the main mix of the UB802 to left or right, depending on the output you choosed.
Of course, even with the UB802 connect to your FW410, you can use the 2 XLR/Jack inputs you got on the FW410.
By the way, you can direct FW410 inputs to your UB802 to have the 2 FW410 XLR inputs on the UB802 which have usefull physical knob.
But, before buying anything, be sure of what you want/need. If you aim to record entire band, want some hardware effects (no latency) or whatever, perhaps you'll better wait to have some more little bucks and buy, for exemple, the UB1204FX-PRO.
What do you think? Of course, you'll always be able to route any mixer to another... But, when we got only few dough, we must lot thought ;)