Mixing oil weights

It's still oil, so a mixture will do its job, which is to act like a lube. It probably won't cure your start up tick. A thicker oil may actually work against that, as it takes just a bit longer getting to where it needs to go.

Use the best filter you can, because you want a good anti-drain back valve. Depending on how the filter is oriented, the better ones will keep oil in the filter longer, helping to get oil up to sooner to help prevent the tick.

After you use this oil, maybe try a 0W-30. It's lighter than a 5W-20 when cold to get to the top end quickly, but heavier when hot, giving you a thicker boundary layer for better wear protection.

Good luck!