Wavy foundation does tend to cause wavy combs of honey, but I've often
noticed that feral colonies or swarms that have been allowed to
establish in empty hives tend to produce wavy combs - maybe there's a
gene for wavyness in bees.
When we put our bees to the heather we only put in starter strips in the
super frames - about 2.5cm (1") of thin foundation along the top bar -
the combs are always pretty straight provided the hives are reasonably
level (not always easy on a heather moor)

Alan Riach - Edinburgh