Swiss visa from London [closed]

According to this Swiss site, the London embassy only takes specific visa categories in person:

National visa for a stay of more than 90 days

• Spouse permit
• Student permit
• Authorised work permit
• Diplomatic permit
• Visa for internship in an international organisation (e.g. United Nations)

Schengen visa for a stay of up to 90 days

• Diplomatic visa
• EU Spouse visa
• Visa for invitations through international organisations (e.g. United Nations)

Other applications go through the VFS.

Embassy/consulate is always better, that's where the visa applications ultimately has to go and third-party visa processing services just take additional time and money while offering little or no benefit to the applicant. For example, it's quite common to get confused or misleading advice from them.

The only question is whether the consulate will let you apply directly. In some situations (family of EU citizens), they have to. In others, they don't. And if they chose to ask people to go through a third party, it's because it saves them money and effort and they almost invariably make it more difficult to contact someone at the consulate directly.

But the decision belongs in any case to the country you are applying to (whether it's made directly at the consulate or back at the ministry of foreign affairs or through some other process is an internal matter), VFS will just collect the relevant forms and data, filter applications and forward them to the consulate, they don't issue visas. It's therefore unlikely going through them will have any impact on the duration of the visa.