I don't know what the other chemicals his homebrew calls for, but you could substitute NaOH for KOH. I'm pretty sure they are very close to a 1 to 1 substitution. If you have the Darkroom Cookbook there is a substitution table in the back.(posted 8154 days ago)NaOH is commonly available as lye, sold in most hardware stores under the brand Red Devil Lye. This is pure NaOH and I use it regularly in my developers. Be sure to mix it in cold water.
I recall, also, a Howard Bond article in Photo Techniques where he discusses making unsharp masks for b&w using TMX processed in HC- 110. I don't recall the issue, but I think it appeared within the last 12 months.
Pat Gainer's vit-c developer (see unblinkingeye.com for the article and formula) produces very neutral gray negatives, which should suit your purposes. You would have to experiment to find the low contrast you need, but I think a good starting point would be 1/2 concentration using his advised normal time for TMX. You might also mix it as separate A and B stock solutions, which would permit you even more flexible contrast control. Email if you want more details.