I have been thinking about kinds of citation rates that distinguish between "trendy" journals, ones what attract lots of citations relatively quickly, and "deep

I have been thinking about kinds of citation rates that distinguish between "trendy" journals, ones what attract lots of citations relatively quickly, and "deep impact journals", where papers published tend to be cited a long time later. Given this classification, you can weight an individuals impact factor by a factor representing how trendy vs deep the venues citations appear in.