How to use abi.encode with ABIencoderV2 in order to encode structs in Solidity ? Or how to use the Muliplex Feature of 0x ?

I need to use the Multiplex Feature of 0x in order to perform a specific trade that perform a UniswapV3 call followed by a _FillOTCorder using the SelfBalance feature of the the Multiplex Feature.

As this is a complex set of code, the best way to do it is to reuse the existing solidity code.
As the order need to be signed, I can’t call multiplexMultiHopSellEthForToken on the proxy contract directly : I need to encode almost the whole call off‑chain in a Solidity vm, then sign it.

It’s often said that structs are just tuples, but before ABIencoderV2 you could pass tuples but not structs to functions and indeed, the following code below doesn’t works :

 calls = abi.encode( abi.encode(subcall.id,subcall.data) ,abi.encode(subcall2.id,subcall2.data)); bytes memory ret = abi.encodeWithSelector(IMultiplexFeature.multiplexMultiHopSellEthForToken.selector, abi.encode(IERC20Token(0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2),IERC20Token(0xdAC17F958D2ee523a2206206994597C13D831ec7),IERC20Token(0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE)), ret2, 0);` 

In details, it correctly generate the 0x5161b966 selector but the initial argument decoding fails and the transaction reverts.