Hi Theo,

the change in level that you are experiencing is probably due to the fact that the filters are not linear phase (to avoid latency): if the crossovers do not affect the overall spectrum, they do affect the phase of frequencies. So depending on signals, it may change the output level (if you change the phase of two sinusoids of different frequencies for example, they may globally add or substract, which can lead to peak level differences). Such phase differences are usually not likely to be heard (especially with small slopes), but it may indeed affect the peak level. That said, most minimum phase multiband tools will have a similar behavior, or will not have a flat spectrum. It is unfortunately a necessary trade-off. We have made the choice to keep the spectrum 100% flat and have no latency, for real time operation. And as you mention it, many people are happy with this choice.

About the external side chain, it has indeed been in our plans for a while, and it still is. We do work on many products in parallel, and we do update the products as fast as we can to include suggestions and fixes (seen the analysis plug-ins recently?). We are sorry if you have the feeling that we haven't heard you.