Cannot verify multiple signatures on SBOM

The cli will allow a user to sign a bom with multiple keys by specifying a different private key in the `--key-file` argument when run multiple times, (It will also allow the user to sign it multiple times with the same private key)
```
cyclonedx-cli sign bom bom.xml
Loading private key...
Loading XML BOM...
Generating signature...
Saving signature...

cyclonedx-cli sign bom bom.xml --key-file private2.key
Loading private key...
Loading XML BOM...
Generating signature...
Saving signature...
```

However when validating the signatures, the cli doesnt allow multiple public keys to be passed in to verify each signature. it fails with a validate error.
```
cyclonedx-cli verify all bom.xml --key-file public.key public2.key
Unrecognized command or argument 'public2.key'

all
Verify all signatures in a BOM

Usage:
cyclonedx-cli [options] verify all

Arguments:
BOM filename

Options:
--key-file Public key filename (RSA public key in PEM format, defaults to "public.key")
-?, -h, --help Show help and usage information

```
when the first key (public,key from the above example) is provided, signature verification fails for all sigs
```
cyclonedx-cli verify all bom.xml --key-file public.key
Loading public key...
Loading XML BOM...
Reading signatures...
Found 2 signatures...
Verifying signature 1... failed verification
Verifying signature 2... failed verification

Signatures failed verification
```
when the second public key is provided, the second sig verifes but the first fails. All are marked as a failure
```
cyclonedx-cli verify all bom.xml --key-file public2.key
Loading public key...
Loading XML BOM...
Reading signatures...
Found 2 signatures...
Verifying signature 1... failed verification
Verifying signature 2... verified

Signatures failed verification
```

Is the ability to sign the SBOM multiple times a feature?
We are looking to leverage the ability to sign the sbom multiple times as it passes through our pipelines, however the lack of verifiability breaks that. any advice would be appreciated.