How to use Transactional API when using Writer instead of Dialer?

[i-fix-retarded-bugs]

Describe the solution you would like

It would be good if Writer supported Transactional API. Currently the only mention of Transactional in this library is Dialer's TransactionalID field.

I have tried to wire a custom kafka.Dialer with that field set into a custom kafka.Transport which is then wired into kafka.Writer, but it results in the following error on every write:
[3] Unknown Topic Or Partition: the request is for a topic or partition that does not exist on this broker
Or just plain EOF sometimes.

Here's the code snippet (not full program):

	dialer := &kafka.Dialer{
		TransactionalID: "my-id",
		SASLMechanism: sasl,
		TLS: &tls.Config{
			InsecureSkipVerify: true,
		},
	}

	tr := &kafka.Transport{
		Context: ctx,
		SASL:    sasl,
		TLS: &tls.Config{
			InsecureSkipVerify: true,
		},
		DialTimeout: 4 * time.Hour, // guard against EOF during debugging
		Dial: func(ctx context.Context, s string, s2 string) (net.Conn, error) {
			c, e := dialer.DialContext(ctx, s, s2)
			return c, e
		},
	}

	w := kafka.Writer{
		Addr:         kafka.TCP(address),
		Topic:        Topic,
		Balancer:     &kafka.Hash{},
		Transport:    tr,
		Async:        true,
		BatchSize:    100_000,
		BatchBytes:   100_000 * 1024,
		RequiredAcks: kafka.RequireAll,
		Compression:  kafka.Lz4,
	}
	defer func() {
		err = errors.Join(err, w.Close())
	}()

Here's how to alter this snippet to make the writer function correctly (comment out the custom dialer and TransactionalID with it):

	// dialer := &kafka.Dialer{
	// 	TransactionalID: "successful_trans_producer",
	// 	SASLMechanism: sasl,
	// 	TLS: &tls.Config{
	// 		InsecureSkipVerify: true,
	// 	},
	// }

	tr := &kafka.Transport{
		Context: ctx,
		SASL:    sasl,
		TLS: &tls.Config{
			InsecureSkipVerify: true,
		},
		// DialTimeout: 4 * time.Hour,
		// Dial: func(ctx context.Context, s string, s2 string) (net.Conn, error) {
		// 	c, e := dialer.DialContext(ctx, s, s2)
		// 	return c, e
		// },
	}

	w := kafka.Writer{
		Addr:         kafka.TCP(address),
		Topic:        Topic,
		Balancer:     &kafka.Hash{},
		Transport:    tr,
		Async:        true,
		BatchSize:    100_000,
		BatchBytes:   100_000 * 1024,
		RequiredAcks: kafka.RequireAll,
		Compression:  kafka.Lz4,
	}
	defer func() {
		err = errors.Join(err, w.Close())
	}()

sasl and tls have absolutely nothing to do with the problem.

So, how to use Transactional API with Writer?

Also, is this library maintained?