The most reliable solution is the cable without daisy chain any active devices. 1500ft PoE+ Switch doesn't require PoE extenders in the middle. It is only the PoE adapter at the edge for return the signal over ultra-long distance. What you need to bury underground now is just the cable.
PoE StandardIEEE 802.3af, IEEE 802.3at, IEEE 802.3bt, Legacy Bt, UPoENetworking Interfaces(8) 10/100 Mbps PoE Ports (2) 10/100/1000 Mbps uplink PortsPoE Port1-8 (Only ports #1- #4 support 800m long-distance PoE, extra POE adapter for the other two long range ports are sold separately.)PoE Total120WPower Supply125WMax. Power Port (port #1-#4)30.28W (328ft), 26.58W (984ft), 23.46W (1648ft), 17.56W (2500ft)IndicatorPWR LNK/ACT PoENetwork media (port #1-#4)100BASE-T: UTP category 3,4,5 cable0500m 10BASE-TX: UTP category 5, 5e cable500800m Bandwidth5.6GbpsSurge ProtectionDifferential mode±2KVCommon mode ±6KV Just Cable between the Switch and POE Adapter Technical Specifications