I myself also doesn´t have a thicknesser.
I cut planks in half (my proxxon goes max 4 cm) so I can cut 8 cm planks. When needed a ´wider´ plank, say 10 cm, I cut the remining 2 cm by hand (small japanese saw) or scrollsaw. The remaining ridge, I then plane.
When I need bigger sizes, I ask my woodsupplier to cut the plank in half for me. He has a prof-saw which can go up to 15 cm (exactly how much, I don´t know), I do know that planks of 30 cm can but cut to the thickness I want 😉.
Therefore I always get the right size/thickness of any type wood of my choise.
I wrote this 'reaction' earlier (more ample) but cannot find it anymore. Did I do something wrong?