Hello,
Thank you for your interest!
Not only DP supports 60Hz on 4K.
HDMI 2.0 also supports 4Kp60.
That Wavlink WL-UG5501H does NOT support 4Kp60. It would got to 4Kp30.
The Wavlink product supporting
4Kp60 is their WL-UG69DK1 dock which supports dual 4Kp60 on HDMI or DP. It looks the same as the one from Diamond Multimedia.
The WL-UG69DK1 cannot be based on the DisplayLink DL-5500 because it supports 5K (by combining two DisplayPort outputs of the DL-6950).
DisplayLink is a semiconductor company so we don't design, manufacture or sell any end product.
Other products using the DisplayLink DL-6950 today are the Dell D6000, Targus has several docks including the one you mentioned, you also have the Plugable UD-ULTCDL.
Some models support USB Power Delivery over Type-C which explains their price...
Some models only feature DisplayLink whereas others combine technology with USB Alternate Mode, which would only work over Type-C connector on platforms having specific hardware inside them (DisplayPort over Alt-Mode, HDMI over Alt-Mode, Thunderbolt...)
You would have to ask the manufacturer if their power adapter is worldwide, but I haven't seen an adapter only working in the US (110V-60Hz) in the last 5-7 years. It cost more money for manufacturers to have different sourcing. If you buy in the US, the plug would be wrong, but that can be changed easily to a European one... We do that all the time for tradeshows.
Kind regards,
Alban