Table elimination does not work across derived tables

create table t1 (a int);

insert into t1 select seq from seq_1_to_10;

create table t11 (

  a int not null,

  b int,

  key(a)

);

insert into t11 select A.seq, A.seq+B.seq 

from 

  seq_1_to_100 A,

  seq_1_to_1000 B;

create table t12 (

  pk int primary key,

  col1 int

);

insert into t12 select seq, seq from seq_1_to_100000;

create view v2b as 

select 

  t11.a as a,

  count(*) as b

from

  t11 left join t12 on t12.pk=t11.b

group by

  t11.a;

explain

select t1.*

from 

  t1 left join v2b on v2b.a=t1.a;

+------+-----------------+------------+------+---------------+------+---------+---------+------+-------------+

| id   | select_type     | table      | type | possible_keys | key  | key_len | ref     | rows | Extra       |

+------+-----------------+------------+------+---------------+------+---------+---------+------+-------------+

|    1 | PRIMARY         | t1         | ALL  | NULL          | NULL | NULL    | NULL    | 10   |             |

|    1 | PRIMARY         | <derived2> | ref  | key0          | key0 | 5       | j5.t1.a | 2    | Using where |

|    2 | LATERAL DERIVED | t11        | ref  | a             | a    | 4       | j5.t1.a | 1    |             |

+------+-----------------+------------+------+---------------+------+---------+---------+------+-------------+

create view v2c as 

select 

  t11.a as a,

  max(t12.col1) as b

from

  t11 left join t12 on t12.pk=t11.b

group by

  t11.a;

explain

select t1.* 

from 

  t1 left join v2c on v2c.a=t1.a;

+------+-----------------+------------+--------+---------------+---------+---------+----------+------+-------------+

| id   | select_type     | table      | type   | possible_keys | key     | key_len | ref      | rows | Extra       |

+------+-----------------+------------+--------+---------------+---------+---------+----------+------+-------------+

|    1 | PRIMARY         | t1         | ALL    | NULL          | NULL    | NULL    | NULL     | 10   |             |

|    1 | PRIMARY         | <derived2> | ref    | key0          | key0    | 5       | j5.t1.a  | 2    | Using where |

|    2 | LATERAL DERIVED | t11        | ref    | a             | a       | 4       | j5.t1.a  | 1    |             |

|    2 | LATERAL DERIVED | t12        | eq_ref | PRIMARY       | PRIMARY | 4       | j5.t11.b | 1    | Using where |

+------+-----------------+------------+--------+---------------+---------+---------+----------+------+-------------+