More availability for Ability Material Mk I

Collecting Characters is fun but an inability to develop these characters due to a limited amount of Ability Material Mk I makes characters hard to advance. Every level of development costs Ability Material Mk I, thus developing characters with 3+ skills is extremely challenging. I have 99 Mk II and 30 Mk III materials at the moment but can't accumilate enough Mk I at a time to develop very many characters to be able to use my Mk II and III materials.

Could rewards and stores provide more availability for Mk I materials? I kind of feel like I shouldn't be carrying so many Mk II and III materials without having more access to Mk I materials.