Dock suggestions that I can connect two external monitors HDMI to my MacBook Pro M4

I would suggest avoiding docks that rely on second-class workarounds like DisplayLink and InstantView.

What you want is a Thunderbolt dock, or dual-display adapter, that supports dual monitors properly, using your M4 MacBook Pro's native hardware-accelerated video.

I would suggest looking at offerings from

• Other World Computing
• SonnetTech
• CalDigit

These three vendors have been in the business of selling Thunderbolt gear to Mac users for a long time.

In addition to their main offerings, Other World Computing has one very cheap option – an OWC Thunderbolt Dual DisplayPort Adapter that goes for $49.99. (SonnetTech has Thunderbolt Dual DisplayPort and dual HDMI adapters that are a bit more expensive). This would be if you just wanted to hook up two monitors and nothing else.

Moving up to a very basic Thunderbolt hub or mini-dock, you might be in the $100 – $150 range (check the vendor sites). Once you get to a full-size dock, you're talking $150 or more.

Many docks that are mainly intended for use with Windows devices rely on software drivers (instead of supporting accelerated hardware) and use things like DisplayLink (and, I presume, InstaView).

What you want are Mac-friendly docks that support multiple displays over Thunderbolt (unless your displays are over 4K, even TB3 will work). Look for docks from brands like OWC, CalDigit, Sonnet and Brydge (Stone Pro). Expect to pay north of $200-250 for a dock that will properly support two displays in extended mode, if you're paying $100-150, you'll get two external displays mirrored at best.

Every MacBook Pro has an onboard HDMI port that provides speeds that are (in certain cases) faster than what can be supplied by a Thunderbolt port. Connect your higher resolution display to the direct HDMI port -- it does not cost you a port to use it.

The second display can be supported with the Apple digital AV MultiPort adapter US$69

USB-C Digital AV Multiport Adapter - Apple