I had the first model LPL 4500 enlarger, how I managed to make it possible to do very large printing was to wall mount the column, there is a simple kit available for this.
When wall mounting affix the mounting kit to something that is proud of the wall, in my case I had the wall mount kit sitting about 80mm out from the wall, I then had a drop table that I made myself which would allolw four levels of table height, plus if wishing to get the biggest enlargement, I could use the floor.
The issues with the vertical column arrangement are when you try to do enlargements over a certain size you will need a drop table so you can enlarge with the head about halfway up only, othwerwise the edge of the column does become an issue with an uncropped negative sometimes.
My biggest enlargements with my LPL 4500 were with 4x5" negs and using 24x30" cut sheet paper. I didn't do this often, but when I did it worked a treat.
Later model LPL 4x5" enlargers also had a 50mm spacer that pushed the head and negative carrier outwards from the column, this was to allow larger enlargements as standard without the bottom of thew column appearing in the printing area.
Mick.