Partionning with preseed

I used to find my solutions on old post here but today I have to write for help as I don't find any usefull answer anywhere. I'm sure you'll rock and help me with this problem I have for quite a while now. So thanks in advance for all your help. I also apologies in advance for english mistakes... (FR)

I try to install ubuntu as following (roughly):

/boot
/efi
LVM crypt
|--> /           ->10Go
|--> /tmp        ->2Go 
|--> /var/log    ->10Go
/opt/space/1      ->25% 
/opt/space/2      ->25% 
/opt/space/3      ->25% 
/opt/space/4      ->25% 

So basically / will be crypted in a LVM, but I want the 4 mains spaces taken around 25% available disk not crypted.

Is it somthing possible ?

When I run my installation, the installer complain I don't have the free space, but I have....

Following pressed and partman file

d-i partman-auto/method crypto
db_set partman-auto-lvm/new_vg_name crypt
d-i partman-crypto/passphrase password WILLBEOVERRIDEN
d-i partman-crypto/passphrase-again password WILLBEOVERRIDEN


d-i partman-lvm/device_remove_lvm boolean true
d-i partman-lvm/confirm boolean true
d-i partman-lvm/confirm_nooverwrite boolean true
d-i partman-auto-lvm/guided_size string max
d-i partman-auto-lvm/new_vg_name string crypt
d-i partman-auto/choose_recipe select mytest

d-i partman-auto/expert_recipe_file string /cdrom/mytest/installer/mytest.partman
d-i partman-partitioning/confirm_write_new_label boolean true
d-i partman/choose_partition select finish
d-i partman/confirm boolean true
d-i partman/confirm_nooverwrite boolean true
d-i partman-md/device_remove_md boolean true
d-i partman-basicfilesystems/no_mount_point boolean false

the partman file:

mytest ::
    538 538 538 free
            $iflabel{ gpt }
            method{ efi }
            format{ }
    .
    512 512 512 ext4
            $primary{ } $bootable{ }
            method{ format } format{ }
            use_filesystem{ } filesystem{ ext4 }
            mountpoint{ /boot }
            options/nosuid{ nosuid }
            options/nodev{ nodev }
            options/noexec{ noexec }
            options/noauto{ noauto }
    .
    10240 10240 10240 ext4
            $lvmok{ } in_vg { crypt } lv_name{ root }
            method{ format } format{ }
            use_filesystem{ } filesystem{ ext4 }
            mountpoint{ / }
    .
    2048 2048 2048 ext4
            $lvmok{ } in_vg { crypt } lv_name{ var_log }
            method{ format } format{ }
            use_filesystem{ } filesystem{ ext4 }
            mountpoint{ /var/log }
            options/nosuid{ nosuid }
            options/nodev{ nodev }
            options/noexec{ noexec }
    .
    1024 1024 1024 ext4
            $lvmok{ } in_vg { crypt } lv_name{ tmp }
            method{ format } format{ }
            use_filesystem{ } filesystem{ ext4 }
            mountpoint{ /tmp }
            options/nosuid{ nosuid }
            options/nodev{ nodev }
            options/noexec{ noexec }
    .
    2048 2048 2048 linux-swap;
            $lvmok{ } in_vg { crypt } lv_name{ swap }
            method{ swap } format{ }
    .
    5000 1000000000 1000000000 ext4
        $defaultignore{ }
        $primary{ }
        method{ format } format{ }
            use_filesystem{ } filesystem{ ext4 }
            mountpoint{ /opt/space/1 }
            label{ 1 }
    .
    5000 1000000000 1000000000 ext4
        $defaultignore{ }
            $primary{ }
        method{ format } format{ }
            use_filesystem{ } filesystem{ ext4 }
            mountpoint{ /opt/space/2 }
            label{ 2 }
    .
    5000 1000000000 1000000000 ext4
        $defaultignore{ }
            $primary{ }
        method{ format } format{ }
            use_filesystem{ } filesystem{ ext4 }
            mountpoint{ /opt/space/3 }
            label{ 3 }
    .
    5000 1000000000 1000000000 ext4
        $defaultignore{ }
            $primary{ }
        method{ format } format{ }
            use_filesystem{ } filesystem{ ext4 }
            mountpoint{ /opt/space/4 }
            label{ 4 }
    .