Thank you for sharing that detailed sample of his writing. I think he is ready for the Spelling List 1's plans in the LA box of Beyond, but I'd do it very slowly, so it is not too much for him. You could spread out 1 day's worth of plans over 2 days, and just take it leisurely. When he does Beyond, he can finish out Spelling List 1's plans, and then begin Spelling List 2's plans, which are also in Beyond. When he gets to Bigger Hearts, he can finish out Spelling List 2's plans (which are also in Bigger Heart's daily plans), and begin Level 2 of Dictation (in the appendix of Bigger Hearts). This is not hard to do and will allow him to have some introduction to spelling without it being overwhelming. However, if you'd rather wait on the spelling, you could have him do his LHFHG Bible verse for copywork instead, and he can do it slowly over the week. I agree that having dc do a lot of invented spelling writing early on can really form some bad habits that can be hard to undo. While doing spelling words in Kindergarten is not something I'd normally ever suggest, your ds is showing a God-given talent for early writing, and simply starting those skills a little early since you already own the Beyond guide and since it will not mess up any future use of the guides and teaching of LA skills, seems to be the best route to go IMO. HTH as you consider what you'd like to do!
In Christ,
Julie