X Carriage selection for CoreXYs? Is there a design that stands out?

Hello, I am designing the X carriage for a CoreXY. I am planning a bowden first but later on I will add a second extruder which will be direct. So one bowden and one direct for the initial set of requirements.

I am wondering if there is a "go-to" design for this that you guys might know about. I am coming from Smartrap Core's boxy X carriage which I am modifying but before I do anything about it I need some good examples. I've been looking at Lulzbot Dual Extruder and others and those are MASSIVE, I can't believe people put something like that on smooth rods (unless they are 12mm)

I will be using linear rods (8mm) for X and those come with their fair stack of issues and considerations regarding weight, balance, etc.

My current mockup looks like this:



It is very simple and at the begining the second hotend will probably be replaced by an inductive probe for bed leveling. For now I am looking for a way to have one of the blower fans cool the hotend's fins without moving it from its position (i'd rather keep the blowers at the back of the carriage) while the other will cool the printed part.

I'm eager to read what you guys use (pictures? please) or what you will point me to.

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