I'm not entirely certain what the features of this particular splitter are, but I think the first question to ask is whether the splitter itself has an EDID signature, before trying to determine whether it passes one or both signatures from the displays. Most of these "intelligent" splitters can only handle a certain maximum resolution, and so it makes more sense for the splitter itself to define its properties.
If you bring up the display preferences panel in system preferences, you should be able to see whether the mini is able to recognize either of the displays connected to the splitter (or the splitter itself). (You can also hold down the "option" key in the display preferences panel to get a "detect displays" button, which can sometimes be helpful when plugging and unplugging displays.)
Deltaco (of course) doesn't manufacture these by themselves, these gadgets are sold with dozens of brands with identical internals. If I connect the splitter to my mini without screens attached to splitter. SysPrefs Displays will tell that the splitter is EP-HDMI-RX, 1080p, 1080i, 720p available without option-key, 50 & 60 Hz.
The splitter should handle 4k@60Hz, so I guess I'm not very near it's limits.
When some destination device is connected to splitter, SysPrefsDisplay will tell the name of destination device.
I guess why this doesn't work with mini+HDMI-245+L2335, is that either the switch converts the forwarded EDID wrong or there is a problem with forwarding hdcp. Like I told, the splitter works with oldAsusLaptop+HDMI-245+L2335.
17sec blinks leads to 59.94Hz / 60.00Hz problem, which leads to EDID forwarding problem. So does that, when L2335 is connected via splitter, SysPrefDisplay says that it's refresh rate is "60Hz(NTSC)" and when L2335 is connected straight to mini, it's only "60Hz". When only splitter is connected there's "50Hz" and "60Hz" and no "60Hz(NTSC)".
Hints for dhcp problem is that it works ok with windows machine and has same problem with all my macs (mini, mp3,1 & mbp2009). I also tested the splitter with 30" Eizo I have. It has one dvi with hdcp and dual-dvi without hdcp. Former socket works, latter doesn't.
I guess, I'm gonna use the mini so rarely for htpc purposes, that it doesn't justify getting another computer for that. Also, it isn't so elegant solution: what do you do if your new splitter doesn't work with old equipment? You renew all your equipment...
If I would try to find a working splitter, I'd need to know how these splitters work, to understand, if there even can be a working splitter with my equipment. Could there be something like "passive splitter" that just feeds the same signal to both ends? Mac would get the EDID and feed the signal as first destination device is connected and second device would just get the same signal? Is this even possible with hdcp? The second device could catch the signal without hdcp and thus decrypted? Or with encryption that it can't open, since the keys are from another device?
Maybe all these "splitters with amplification" that can feed both ends of the split simultaneously can have same problem than mine, so I shouldn't try to have same display at my monitor and my projector?
Simultaneous feeding of two destinations needs the splitter to select EDID components from both display devices and ask the sufficient signal from the source, so that both display devices can show it?
Solution would then be to use simple mechanical, manual splitter switch, when mini gets only the EDID of switched device and nothing from the other or the splitter itself?
The problem in this age is that selleres and even "brands" don't understand the inner life of their products. Even Deltaco was surprised about my findings of their device...
Anybody know if this is real passive mechanical manual "no intellignce or EDID inside":
https://www.amazon.com/Bi-direction-Manual-Switch-Passthrough-Supports-DotStone/dp/B01L8LLP2G/ref=sr_1_3?rps=1&ie=UTF8&qid=1507394946&sr=8-3&keywords=hdmi+splitter+manual+bi-direction&refinements=p_85:2470955011,p_76:2661625011
?
Deltaco has this under HDMI-7017 (
https://www.deltaco.se/produkter/deltaco/deltaco-prime/HDMI-7017 ), but their support probably mixed this with some other model and started to telling about automatics and remote controls with this model...