Bonding two connections into one using two Balance 20s?

I have a DSL and WISP available at my house (DSL = low latency, low download/upload, WISP = higher latency, higher download/upload) and I would like to combine/bond both of these connections into a single connection to achieve low latency and high download/upload speeds as well as for failover in case one goes down. My brother is located 30 minutes from me and has Google Fiber (gigabit plan). Could I purchase two Balance 20’s and place one device at my brother’s house and then link the two units together to achieve this? Would I be able to benefit from low latency (DSL) and high download/upload (WISP) or would one connection bottleneck the other? Also, would I need to purchase anything additional (e.g. licensing) to make this work?

have you considered starlink as primary and wisp/dsl as backup WANs?

I would be on a wait list for over a year and I have heard from neighbors that the speeds aren’t that great for what you pay. My WISP is able to offer me 160D/35U which I would say is better than Starlink but it does have tower outages every so often that can last for hours/days.

I’m willing to buy two peplink devices assuming it would be a fixed cost without the need for a speedfusion connect subscription. The other options I have are: 1) turn-key software solution such as speedfusion connect or speedify, or 2) OpenMPTCProuter (open source + VPS rental)