The Tinyproxy package is currently on version 1.8.3-2. The latest release is version 1.8.4 (released on Jan 1st 2016). However, since then additional features have been commited to the project, most notably the support for SOCKS proxy.
Would it be possible to compile the package from source and integrate this into OpenWRT/LEDE through the official package repository, or do we need to wait for a new release before it can be formally integrated?
If you build your own from source, it may be as easy as editing the Makefile. When I was working with wpa_supplicant source, changing the PKG_SOURCE_DATE and PKG_SOURCE_VERSION for a git checkout was sufficient to get a functional build for me.
PKG_MIRROR_HASH - SHA256 checksum of the tarball generated from the source repository checkout (previously named PKG_MIRROR_MD5SUM). See below for details.