Mining to your old address is fine, you just need to follow some rather complicated instructions to use that address in the new version wallet. I suspect this will be true even for the GUI wallet which will eventually be released. The instructions are posted to a reddit thread:
https://www.reddit.com/r/IntenseCoin/comments/89gw15/guide_converting_your_141142_wallet_to_the_145/
Very important: you have to extract the 4 keys from the old wallet (e.g. - 1.4.1 or 1.4.2) to restore that address in the new wallet. Do that now if you haven't done so already because those keys are also the only way to recover your balance if something happens to the wallet file (there is no 25 word recovery seed, AFAIK).