Don't worry, franky1 gave a bit more detail in case my wording could be considered as misleading.
There is no "reserved for future use". Franky is a misleading statement incarnate.
The Segwit testnet mined a 4MB block, just by including alot of multi-signature transactions (which obviously have a much heavier transaction:signature ratio than regular transactions)
Do you have any arguments that don't involve subverting plainly observable facts?
much like bitcoin testnet got its 7tx/s.. but never happened in reality on bitcoin main net after 8 years of trying
which is why devs are thinking about other novel things to append to transactions such as confidential commitments to fill up atleast 1.9mb gap. because the 2.1mb fill isnt even going to get reached