Hello IIGnomeII,
Think very carefully before removing that foam.
Most tinny's have inadequate positive flotation and will sink like a stone or roll inverted when flooded.
Foam under the gunnels is intended to prevent the capsize.
If you are that short of storage maybe that is nature's way of telling you that you are taking too much stuff.
4.5m boats have plenty of room for storage boxes etc.
I once tested my 12 foot tinny by taking off the motor and replacing that weight with house bricks.
It was a well regarded brand and it sank like a stone, I was much more careful after that.