Is it possible to install OpenIndiana without the default DE, or did you just disabled the DE and installed E22?
I just installed the whole thing with Text installer, then refreshed hipster IPS publisher (the official repo) and installed E22 from it (openbox, awesome-wm, notion-3 are available too), keeping MATE as fallback. Obviously if you have LightDM or XDM services enabled, you'll have to add Enlightenement to .xprofile or .xsession respectively.
What package repositories are you using?
The only way to achieve a more diverse software availability on OI, is using Joyent's pkgsrc binaris for Illumos, which - god bless pkgsrc - adds tons of more packages (e.g. i3, XFCE, Darktable, Firefox Quantum) and works shamelessly on OI.
Yet, I see OI development is progressively slowing down, to the point they contribution is become clone to insignificant in the Illumos world; and as I mentioned above, SFE repo is dying. That's way I've moved completely to Tribblix meanwhile: simple, lightweight, old-school distribution, installs automatically in 2 minutes with a sh script, reminds a lot NetBSD and Slackware; uses classic SVR4 packages, grouped in overlays (meta-packages) to easily manage through its zap() utility; supports IA-32, SPARC64 as well as UFS-root too, all things which are rare nowadays in Illumos. Tribblix software availability is at least 2x than OI; additionally, a pkgsrc bootstrap is pre-configured as a zap overlay. There's also a tool, named ips2svr4, to convert Solaris IPS packages to SVR4 format.
zap is an awesome util, in the way it can perform major system upgrades and can manage zones; oh, and the Tribblix variant named OmniTribblix allows building LX Zones.
Last but not least, the creator wrote several useful managment tools in java (see tribblix-tools overlay)
It's sad to admit that while OI was migrating userland from python 2.7 to 3.5, Tribblix was moving to python3.7 already
Anyway, this is Tribblix 0m20.5 with CDE 2.30_1 running on my Pentium 4 Netburst from 2000, UFS root