future-proof means that it's a scalable environment that won't get clogged once it reaches congestion as basically all the blockchains that are now competing directly with Bitcoin. Mintlayer uses the same approach as Bitcoin to scalability: layer 2 (lightning network) and maximum efficiency possible on the base layer (signature aggregation, batching & coinjoin (combined with sig. aggregation), turing-complete scripting system, limited blocksize, etc.). The DEX transactions can be performed offchain, while there are no onchain trading books like it happens in AMM trading (e.g. Uniswap).

Mintlayer is bound to Bitcoin and programming language remains Bitcoin script even if Bitcoin upgrade to new functionalities. In fact, Mintlayer uses Bitcoin script but it introduces a few OP_CODES that are new. To remain compatible with Bitcoin there is a way to identify the type of script being supplied. If it's version 0 then we assume all op codes follow the bitcoin script, otherwise it's something developed specifically for Mintlayer. In this way we avoid that Bitcoin introduces a new OP_CODES with the same name but different functionality (let's say if Mintlayer implements an op code with the code 0xCD with a particular functionality, a year later bitcoin script implements a new feature and recall it with the same name 0xCD)