I practiced Tomiki-ryu for many years and still use his kata system as a base for my training.
I think that "ikkyo" is built into the foundation of: aigame ate, gyaku gamae ate, and gedan ate for example. The Tomiki version of those waza are answers to "what if" ikkyo doesn't work. If you're doing the kuzushi properly for those waza, you should'nt have trouble with ikkyo.
A bit of advice: Don't look so much at the differences in the two practice methods, give attention more to the similarities. There are way more similarities than differences.