relevant parts of rc.conf:
cloned_interfaces="wg0"
ifconfig_wg0="inet 10.2.0.2/32 fib 1"
static_routes="vpn"
route_vpn="0.0.0.0/0 -interface wg0 -fib 1"

pf.conf:
tcp_services = "{ domain, ntp, http, https, 222, 9091, 51413, 445 }"
udp_services = "{ domain, ntp, 51413 }"
ext_if = "em0"
vpn_if = "wg0"

block all
set skip on lo
pass out inet proto icmp from any to any # ping
pass in proto tcp from any to any port $tcp_services
pass in proto udp from any to any port $udp_services
pass out

relevant part of speedtest-go:
✓ Latency: 9.894948ms Jitter: 407.216µs Min: 9.409548ms Max: 10.935749ms
✓ Packet Loss Analyzer: Running in background (<= 30 Secs)
✓ Download: 419.76 Mbps (Used: 516.43MB) (Latency: 1698ms Jitter: -9223372036854ms Min: 13ms Max: 6665ms)
✓ Upload: 171.84 Mbps (Used: 303.84MB) (Latency: 19ms Jitter: 3ms Min: 13ms Max: 25ms)
✓ Packet Loss: 55.37% (Sent: 266/Dup: 0/Max: 595)

$ doas setfib 1 netstat -rn
Routing tables (fib: 1)

Internet:
Destination        Gateway            Flags         Netif Expire
default            link#3             US              wg0
10.2.0.2           link#2             UH              lo0
127.0.0.1          link#2             UHS             lo0
192.168.1.0/24     link#1             U               em0

$ cat /etc/start_if.wg0
/usr/bin/wg syncconf wg0 /usr/local/etc/wireguard/wg0.conf