For a long time I have been a firm believer in putting a NUC, power dist. and a 50u multimode fiber transceiver (if a permanent installation) at the balance point of the OTA. Run 13.7V power, fiber and RS-232 down from the NUC. RS-232 to the mount. FTDI USB adapter at the NUC. Fiber transceiver next to the NUC. All short, high-grade USB cables. HDMI spoofing adapter plugged into NUC. Maybe a high-grade USB3 hub, if needed. Don't mix USB2 and 3 devices on same hub, if possible. Main cam connected directly to NUC.
1. NUC means I can use ASCOM, APCC, Horizons, SharpCap, PHD2, MaximDL, Nebulosity, PixInsight, etc. Maximum ASCOM devices and drivers supported.
2. Minimal, tough cables coming down from OTA.
3. Minimal lengths and movement on fragile, temperamental USB cables.
4. RS-232 cable going down to the mount for the absolute most stable and reliable connection possible.
5. 50u multimode fiber communications in and to the observatory for maximum protection from ESD, GPR, RFI, EMP, etc.
6. Big batt under the tripod/pier. If a permanent setup, a big UPS at the base of the pier/tripod and a remotely-controllable PDU, such as is made by Digital Loggers. Big surge protector/line filter protecting UPS, PDU and fiber transceivers/hybrid network switch.
I hope this helps.