I can assure you that even though you don't understand the theory behind what I'm doing, these ideas work spectacularly in practice.
I'm not talking about whether your ideas work "spectacularly in practise", almost certainly they don't and you just like it that way or, just maybe they do work but the issue I'm talking about is fidelity, not how good your system sounds to you and your friends! I'm using the true meaning of the word "fidelity" here - trust in a system reproducing what was intended, as opposed to reproducing something which sounds good. This is an important distinction because the two can be quite different, massively so in some/many cases. As I mentioned previously, commercial films and music are mixed on systems with matching 3 front speakers. Having a far more directional centre speaker with different crossovers and a different sound presentation might sound good to you, it might even sound good to others but it almost certainly cannot score highly as far as fidelity is concerned. Likewise with your two "fill" front speakers, if you have a gap in your image then there's something quite seriously wrong with your system setup, maybe your L/R speakers are far too widely spaced, maybe they're under powered or under driven or possibly you're looking for the same presentation from your L/R speakers in a surround setup as you would get in a stereo setup.
Going back to what pinnahertz was talking about previously. In a surround system, bass accuracy is always a serious problem in a small room, there isn't any cure for this problem. In virtually every situation though, spreading the bass between two or more physical subs produces a very significant improvement, not a cure but far better than anything you can realistically achieve with just one sub. Two small subs as opposed to one big one is, in pretty much every conceivable practical consumer environment, going to give significantly higher fidelity.
I'm going to continue to share my experiences. I think they're valuable to people who want to efficiently put together great sounding speaker systems in their homes.
I'm not so sure your experiences would be valuable to others. Even if we hypothetically assume your system does produce high fidelity, it would do so only because of a number of unusual simultaneous quirks of your particular listen environment. I personally would therefore not recommend your setup to others and IMHO is likely to confuse them and result in lower fidelity.
There's a bit of variability to how multichannel music is mixed, so there really isn't a "one size fits all" solution.
There's a multichannel Mancini SACD that has an LFE channel that is so low, my AVR can't boost it enough to make it audible.
1. There is massive variability in multichannel music mixing. Unlike with films and even TV, there are no standards or hardly even any conventions. It's impossible to get a setting that provides simultaneous fidelity of music mixes and films!
2. SACDs, unlike most other 5.1 mixes, are not supposed to have +10dB on the LFE channel. Additionally, if your AVR/sub cannot achieve a +10dB boost, then it cannot be a properly balanced system in the first place.
G