External FX Dual mono/stereo

I have DBX 266XL compressor which I can use as two mono compressors or one stereo-compressor and 2 DBX 163X which can be linked to be used as a stereo-compressor.
The problem is that I can only use these either as one or the other, because inputs cannot be shared between multiple external FX.

I was wondering how you guys handle external effects which can be both used as a dual mono effect or stereo effect?