100% Kanuma or a Mix?

I have a 40 yr old Brush Cherry which has never flowered since being in my care. I understand that this tree is an acid loving, tree, and potentially incorrect soil is one 0f the reasons it is not flowering (among others!!).

I am thinking of using Kanuma soil next time I repot this tree, but I have never used this substrate before.

My question is, should I use just 100% Kanuma soil, or should I use a mix?

If I should use a mix, which substrates are best and in what ratios? Eg pumice? Lava rock? Akadama?

Please bear in mind that I am a relative novice in bonsai care.

Thanks for any advice

I just use a small part of peat in my mix and use RO water for my acid loving trees. That is what I can source locally. If I lived in Japan, I may consider kanuma. But here it is not financially appropriate. Just look for local acidic substrates and don't underestimate the quality of the water you give the tree.