No simple way to modify partition layout after running a guided configuration

[Pityesz Csillagszemu]

Hello,

I recently installed Ubuntu 19.10 on x64 from the netboot image (though this has been an issue for me for a long while).
Basically what I would like to achieve is to get a recommended partition layout _template_ during installation which I am able to fine-tune for my needs. In this recent example of mine the Guided encrypted LVM script reserved roughly 500MB for EFI and 700MB for /boot on a relatively small 32GB disk which are way too conservative for me (space used on EFI is 8MB - 1.6%! - not expected to grow any further!; space used on /boot about 150MB - 21% -, roughly 70MB/kernel at the time of writing so theoretically 300MB should give enough headroom for the next couple of years). This results in nearly 1GB of space lost on an already limited capacity drive.

Though the problem is if one runs the Guided partitioning script (especially the encrypted LVM one) there is no easy way to modify the partition layout. The encrypted and LVM-root partitions cannot be deleted, moved or resized after the Guided partitioning option was chosen. Also the partitions will not get aligned correctly if they are manually resized (creating a partition after the preceding one is resized will result in empty space between them.)
I believe it would increase the user experience of linux installation a lot by making it a lot less worrisome if the partitioning scheme was more flexible and could be fine-tuned more easily during installation.

Cheers.