The magical solution to splitting his focus had two approached, at least Eldrian had found two. One, he could reprogram what the spell needed to do. By envisioning the start, middle, and end, he could more or less make the spell self reliant.
This envisioning would be through mageia, instead of mana. The method of forming it was similar in manner to how Eldrian talked telepathically with Ceph. It was more leaving delayed instructions than actually controlling the spell. But it worked—for simple spells.
The other method was similar, but Eldrian left it blank. Allowing himself to shift his 'focus' or mind to it to alter things, but leave balancing the spell to a sort of artificial magical mind.