Wish I had found this thread earlier, reading through now... BUT this particular thing I know the answer to.
On all the newer bitmain stuff you can't mine directly to a wallet, older sha-256 you can. I'm not 100% sure on s9's since I
do not have one. That being said: --disable-libcurl <-- there is the issue. You can compile with disabling libcurl, but you get
errors if you leave it enabled. (I'm trying to look and see what the deal is there.. but libcurl is what is needed for it to accept
getwork and GBT which is needed if it directly connects to a wallet.)

I've been trying something on my own, but would have saved myself ages if I had found this thread earlier. hehe.
If I sort out what the deal is with libcurl I'll be sure to post something about it. I'm cross compiling as well and really
going through each problem by hand having never cross compiled anything before was...  screamy-stabby-feeling.
I should search through topics more often. Hahaha.. but I have to admit I've learned alot so might have been worth it.