1) Is asicboost a hardware or software optimisation?
According to my current understanding, asicboost optimizes mining through forming a merkle root of special kind. That sounds like it should be implemented in software? Does hardware need to be designed in special way to take advantage of optimized merkle roots? If so, can such special hardware be used to mine regular, unoptimized blocks?

2) Is asicboost (as the name suggests) applicable only to ASICs (not to GPUs, FPGAs)? If so - why?

3) Does observing of empty blocks from a miner increase our suspicions of asicboost being used?
I guess, that since they need a special merkle root, it may happen, that an empty or almost-empty block provides a necessary merkle root, so they just keep mining such an empty block until it is mined or an optimized merkle root found for a filled block, whichever happens first?

4) If it's all about special merkle roots, why couldn't we detect asicboost optimized blocks just by analysing the blocks and their merkle roots?

I suggest staying purely technical, apolitical. Therefore I made this thread self-moderated.