Mikrotik asymmetric non-matching bonding? (L4 aggregation)

Hello,
We are using an extra linux box with custom configuration as aggregators to achieve bonding of different medias with asymmetric and nonmatching bandwiths. For example we are bonding a cable modem using ethernet 15/1,5 and a DSL connection 8/2 into a single connection roughly 23/3,5 that you see 22-23/3-3,5 if you do bandwith test.
I was wondering if Mikrotik has, or will have support for that type of bonding. For example I create 2 different gre tunnels to a remote destination using different connections, and Mikrotik bonds these tunnels into one single connection?

Thanks!