Yes - you can set certain parameters during the installation (minfree, maxroot, ..) which all influence how much space is allocated to what.
Afterwards you can also modify the disks (e.g. you can remove the thinpool from the local-lvm storage, increase the size of the root-lv and then the filesystem on top)
There are quite a few threads in this forum (and of course also elsewhere in the internet) where this is described pretty well
I hope this helps!