It is possible to use SliceX together with almost any third party effect and even to create a custom template to make it easier to do that. (See this tutorial: https://vimeo.com/124020187 )
We included a template in the "SliceX Extras" folder for some time that was premade for using Color Finale together with tracked masks if you owned both SliceX and Color Finale. However as of December 2017, users have complained that there is a pixel shift when using this template (the results inside the mask are shifted a few pixels to the left). For a color correction tool, this is not an acceptable result. We investigated this and we do not see any issues combining SliceX with other third party tools, and have provided information to Color Finale to help them solve this.
However we also feel it is prudent to remove the template from our installer, since this issue is beyond our control and not something we can fix on our own.
You can download the "Color Finale With Shape Mask" Template using the link below if you wish to use it with the understanding that CoreMelt cannot support this template or help with this issue.
We are happy to assist with any other issues with our products including questions regarding combining SliceX with other third party plugins.
To install, unzip the file into /Library/Application Support/Final Cut Pro/Effects.localized/SliceX Extras