The Winner is LG V35 ThinQ !
It is the only device that both fully supports Google Fi, and Firstnet, and also supports HDMI out. (Requires USB-C to HDMI adapter.)
The Pixel 4 supports both networks, but does not have HDMI out.
Designed for Fi models
From: support.google.com/fi/an…
- Pixel 3 and up (North American versions)
- Pixel 2 (North American and rest of world versions)
- Pixel 2 XL (North American and rest of world versions)
- Pixel Model G-2PW4100 (North American version)
- Pixel XL Model G-2PW2100 (North American version)
- LG G7 ThinQ (Unlocked North American versions sold by retailers)
- LG V35 ThinQ (Unlocked North American versions sold by retailers)
- Moto G6 (Unlocked North American versions sold by retailers)
- Moto G7 (Unlocked North American versions sold by retailers)
- Moto G Power & Moto G Stylus (Unlocked North American versions sold by retailers)
- Android One Moto X4 (North American versions)
- Nexus 5X Model LGH790 (North American version)
- Nexus 6P Model H1511 (North American version)
- Nexus 6 Model XT1103 (North American version)
Band LTE 14 Firstnet phones
From: www.firstnet.com/content…
- LG LM-V350AWM V35 ThinQ FirstNet Ready Yes
- LG LM-X410AS K30 FirstNet Ready Yes
- LG LM-Q710WA Stylo 4 FirstNet Ready Yes
- LG LM-V405UA V40 FirstNet Ready Yes
- LG LM-G820UM G8 FirstNet Ready Yes
- LG LM-X420AS K40 FirstNet Ready Yes
- LG LM-X320AA Prime 2 FirstNet Ready Yes
- LM-Q720AM Stylo 5+ FirstNet Ready Yes
- LG LM-G850UM G8x Thinq FirstNet Ready Yes 3 LG
- LM-V600AM V60 ThinQ FirstNet Ready Yes
- Google G020I Pixel 4 FirstNet Ready Yes
- Google G020J Pixel 4XL FirstNet Ready Yes
- Motorola XT1922 Moto G6 Play FirstNet Ready Yes
- Motorola Lex L11n FirstNet Ready Yes