A Lot has changed there. Solo mining is still allowed but I don't think you will be able to hit a block with a solo mining wallet. Try using solo pools they might help
Solo mining is solo mining, mining to you own private node or a public solo pool makes very little difference in
finding a block.
Now, having your found block confirmed by other miners so the chain is built upon it is a whole different story -- damn good chance that some pool will have a block found perhaps very soon after and because of their faster connections to the BTC network their block gets confirmed before yours shows up on the network meaning you lose an orphan race.