Based on the theory that cross breeding happens at planting time - You might add a little description during planting to try planning to plant nine spaces. Start with slot 8 and put an cheaper seed there that you cross with slot 1. This will let the plant at slot 1 crossbreed with slot 8. After planting slot 1, then pull up/remove slot 8 - and plant from 2 through 8 - just like you suggest.

Using your example - to try to get all slots to try to cross breed - I'd plant slot 8 as honey lemon (the cheaper seed), then slot 1 as pineapple, pull up slot 8, then continue planting from slot 2 through 8 (honey lemon, pineapple, etc).

I'm experimenting with starting in slot 8 with the cheaper seed (Chamomile) - to get slot 1(Azeyma Rose) to crossbreed. I'm hoping for eight cross breedings with a result of Halone Gerbera. I'll post the results once I see how this idea works out.