innodb reading deleted rows improvement suggestion

Since innodb stores its data as a clustered index around technical or live primary key, we decided to improve the deletion performance by only logically deleting leaves to avoid tree balancing.

since all leaves are linked to an upper level descriptor block, could we mark the whole block as deleted when all the downward leaves are marked for logical deletion ?

this means we would not have to parse the leaves to find out they are deleted since we could discard full blocks instead, it should speed up reads on higly deleted tables.

also since we can estimate the number of rows and blocks ( thanks to the balanced nature of the tree ) that are deleted we would have afiner grained pki of the reclamable space of any table.