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I've read that in a slant plate LM still (boka style) having the slant plates too far apart can cause excessive vertical drop from the top plate to the bottom resulting in "splashing". This makes sense. Of course, conversely if the plate separation is too close then you get a bottleneck in the vapor path... which is of course, bad.

But what I'm wondering is, "Is excessive gap/drop and potential splashing necessarily a BAD thing?" I mean, if any of the collected distillate splashes out of the bottom slant plate, it just falls down the column increasing the reflux ratio. How is this a bad thing? In fact, the only situation in which I can think this might be a problem is when running a boka in "potstill" mode for maximum takeoff rate - you wouldn't want unintended reflux falling back down the column.

Anyways, if splashing is actually a concern in slant plate column designs, could the top plate be recontoured to direct flow to the sidewall where they could channel down the sidewalls of the column intil the bottom plate intercepts the flow? Or maybe the pagoda/cup-and-tee LM design is better than the slant plate. Just some a thoughts.

To the best my knowledge, splashing on dual slant plates was first observed by Odin in a glass boka (you can find video footage on YouTube somewhere). He determined this has a negative impact on the design. How much of an impact I do not know...

One of the unintended benefits I encountered from adding an external reflux circuit to my dual slant plate is that it eliminates splashing on the plates. If it is really a problem then this is one way to fix it.

That's what I'm trying to rationalize... why would it be a negative impact of the design?

Also, in your design, I'm not seeing how an external reflux return would reduce the splashing problem. Wouldn't the upper plate in that setup still be dropping distillate into the lower plate to create splashing? If there is no upper plate, wouldn't column falling from the coils (presumably as high or even higher than an upper plate) still create splashing?

There may be a little bit of splashing, but not much as the bottom plate does not hold any liquid.