Alternative private hospitalization insurance other than 7 IP providers?

30s (F), wanting to upgrade IP from B1 to private but was declined by current provider due to pre-existing condition. While I have never been hospitalized, other IP providers have offered private coverage, but exclude the pre-existing condition. I have heard that we should never switch IP providers. Are there other private hospitalization insurance available to Singaporeans that supplement IP (besides lump sum CI payouts / International health insurance)?