Monitor Out Main Out Sum or split

I did a search and couldn't see that this was clearly answered. I assume the main out XLR left right is not summed if using only the left output. I assume that using the 1/4" left it is summed if only connected to the left output. Is using the monitor out a summed output? Can someone please confirm if they know for sure. This is typical for outputs, but wanted to make sure. I would then change my master volume to control my FRFR & connect to monitor out and use the main out to the FOH. Currently I use the right XLR to FOH and left XLR to FRFR(Monitor).

The main reason I was asking is for stereo effects. For example the stereo widener(multiple delays etc.) would not give full results if through the xlr main out (single left or right cable output) as it is not summed. It would however work on the monitor out. Typically the 1/4" is summed if a single output connection is used (i.e. left out). Please confirm if this is correct.

ok we keep doing this partial stuff.....last part of the question. What about the 1/4" as this is not typical if that is the case. It is for XLR so nothing is really different, but 1/4" not summed out the left side with one connection? Not a big deal just want to make sure.

easy........ There were three parts to the question:

Monitor out - Answered (summed)
main out (XLR's) - Answered (not summed)
main out (1/4) - not answered. Did not see clarification to differentiate this from the xlrs.

These are usually different as the XLR's are balanced and 1/4 is not. In the typical connections if you connect (1) 1/4 to the left side it gets a summed output.