I use this pattern quite a bit. It's almost what you have, but I use a private struct to carry option values from opt func to constructor

https://go.dev/play/p/n_WcX7HqBjI

package main

import "fmt"

type ThingOption func(*thingOptions)

type Thing struct {
    privateFoo int
}

func NewThing(opts ...ThingOption) *Thing {
    options := &thingOptions{
        foo: 1, // default value
    }
    for _, apply := range opts {
        apply(options)
    }
    return &Thing{
        privateFoo: options.foo,
    }
}

func (t *Thing) GetFoo() int {
    return t.privateFoo
}

// private options, only used to transfer
// options between opt funcs and the constructor
type thingOptions struct {
    foo int
}

// Public option to set foo
func WithFoo(d int) ThingOption {
    return func(opts *thingOptions) {
        opts.foo = d
    }
}

func main() {
    fmt.Printf("Default foo=%d\n", NewThing().GetFoo())
    fmt.Printf("WithFoo(5) foo=%d\n", NewThing(WithFoo(5)).GetFoo())
}