Can easily apply yourself, show you work online, submit business registration docs, permission letter to work remotely in Thailand. I recall someone from the UK posted about applying via book keeping/accounting. Their post maybe in the threads.
You show how you work online and provide evidence of your income via bank statements then you can apply via workcation.Submit contract of employment and letter detailing permission to work remotely in Thailand.
New businesses have been approved but SP will be simpler. You would need to inform them the reason for no income applying via workcation. Where are you applying?