For logs, I've used latex paint and had some cracking. I've not had any cracking with different waxes.

Thru my business I get a lot of types of candle waxes, and have tried many of them. They all work fine.

I think it's best to melt some in mineral spirits. I melt enough such that when it cools it's brushable but thicker than paint. If it starts to separate in the can - which it can depending on how pure the paraffin is - then a little stir will emulsify it enough to spread. Having it brushable results in an even thin coat. I double coat crack prone areas, like the end grain or pith area.

You can improve the wax's ability to stay solubilized in the mineral spirits by using a softer wax - or even old candles that leave a fingerprint when you press on them.