I own ttCMS and DCP-Portal. ttCMS was my fork of DCP-Portal. I ended up buying DCP-Portal code and websites back in 2004 and maintained both ttCMS and DCP-Portal. Both ttCMS and DCP-Portal were regular winners of Content Management Systems competitions including jointly winning first prize in a Byte magazine shoot-out.
I withrew the code in 2012, and maintained a few websites based on DCP-Portal until about 2018.
I am working on a revival of DCP-Portal. I plan a release sometime near the end of the first quarter of 2016. Not only is the code base being modernized to support PHP version 8, but also the simple templating engine. (ttCMS, as a form, will remain a "dead" project).
I decided tackle the admin control panel first. It's by far the most static of the designs.
And to answer the question: How practical is classless CSS for projects? ... not practical as a total strategy. I discovered early on in this DCP-Portal project that a method to identify HTML elements is needed – particularly as the complexity of pages increases.
I'm attaching a screen shot of the Admin Control Panel interface. It includes a new sidebar menu, a new header infobar, new forms that support icons, new footer section, and a renewed data section. The stats panel is moved to the top and will provide more information. You can, of course, click on the screen shot to see the full size version.
It's clear in doing this project that classes are a necessity for complex projects. And it doesn't take much to make a project complex.