amazon-ebs builder fails with default vpc, spot, and multiple instance types

In a generic example where I only define a default vpc_id, spot_instance types (p3.8xl,p3.16xl, and g4dn.12xl). You get the error below. Is it really iterating through each instance type in each AZ. These instances are certainly support in a subset of the AZs:

```
amazon-ebs: Created Spot Fleet launch template: lt-0c8767009c99dd8e7
==> amazon-ebs: Error waiting for fleet request (fleet-b0de6755-a375-2dd9-a412-a30029dd212a) to become ready:
Your requested instance type (p3.8xlarge) is not supported in your requested Availability Zone (us-east-1f).
Your requested instance type (p3.16xlarge) is not supported in your requested Availability Zone (us-east-1f).
Your requested instance type (p3.8xlarge) is not supported in your requested Availability Zone (us-east-1a).
Your requested instance type (p3.8xlarge) is not supported in your requested Availability Zone (us-east-1c).
Your requested instance type (p3.16xlarge) is not supported in your requested Availability Zone (us-east-1d).
Your requested instance type (g4dn.12xlarge) is not supported in your requested Availability Zone (us-east-1b).
Your requested instance type (p3.16xlarge) is not supported in your requested Availability Zone (us-east-1a).
Your requested instance type (p3.8xlarge) is not supported in your requested Availability Zone (us-east-1b).
Your requested instance type (g4dn.12xlarge) is not supported in your requested Availability Zone (us-east-1c).
Your requested instance type (p3.8xlarge) is not supported in your requested Availability Zone (us-east-1d).
Your requested instance type (g4dn.12xlarge) is not supported in your requested Availability Zone (us-east-1f).
Your requested instance type (g4dn.12xlarge) is not supported in your requested Availability Zone (us-east-1d).
Your requested instance type (p3.8xlarge) is not supported in your requested Availability Zone (us-east-1e).
Your requested instance type (p3.16xlarge) is not supported in your requested Availability Zone (us-east-1c).
Your requested instance type (p3.16xlarge) is not supported in your requested Availability Zone (us-east-1e).
Your requested instance type (g4dn.12xlarge) is not supported in your requested Availability Zone (us-east-1a).
Your requested instance type (p3.16xlarge) is not supported in your requested Availability Zone (us-east-1b).
Your requested instance type (g4dn.12xlarge) is not supported in your requested Availability Zone (us-east-1e).
==> amazon-ebs: No volumes to clean up, skipping
==> amazon-ebs: Deleting temporary keypair...
```
Here is the builder spec:
```
"builders": [{
"type": "amazon-ebs",
"region": "{{user `region`}}",
"source_ami": "{{user `build_ami`}}",
"run_tags": {
"Name": "packer-gpu-processor-{{user `flag`}}"
},
"vpc_id": "{{user `vpc_id`}}",
"security_group_ids": "{{user `security_groupids`}}",
"spot_instance_types": ["p3.8xlarge","p3.16xlarge","g4dn.12xlarge"],
"spot_price": "auto",
"ssh_username": "ec2-user",
"ami_name": "al2-gpu-efa-fsx-processor_{{user `flag`}}-{{timestamp}}",
"launch_block_device_mappings":[{
"delete_on_termination": true,
"device_name": "/dev/xvda",
"volume_size": 100,
"volume_type": "gp3"
}]
```
packer 1.7.3