I do the same . I come in April for 4 weeks , July and October also for 4 weeks . All on 30 visa exemption. I get a tourist visa in December as I Come for 6 weeks . Never had an issue yet . Maybe the IO never had there coffee or their Kratom yet
You have the money 2 months before and 3 months after . You can only spend 400 of that and you have to top it back up to 800 2 months before your due to renew