The first improvement was this position submitted by Alan Aspinwall, which he developed without seeing the position above.  It incorporates some clever clustering to maximize the mobility of the grasshoppers and beetles.

Based on Rathstar's design (an unfair advantage) I added a trick of my own, by bending the lines to create a door and positioning the spiders just outside the door, you can increase the mobility of the spiders.

A completely different approach by "Dreadpirate" produced this 162 move masterpiece.  The closed loop frees all the pieces to move.   I suspect that if the challenge was to find the most moves for both players, this would be close to the best possible for that, too.

Or perhaps, "deathstar" would be a better name.   Using a completely different approach, leaving three undropped pieces and maximizing the spaces available to drop into.  This one broke the bank that was funding the challenge.

Kudos to Woswoasi who pointed out the the previous published count of 204 for this position  was incorrect.

Combining ideas from all the previous setups.  Put the placed beetle on top for maxumim mobility, and position the spider at a door for 2 extra points of mobility.

Kudos to Woswoasii who pointed out the the previous published count of 214 for this position  was incorrect.

Reverting to a symmetric plan, Woswoasi came up with this simple pattern which maximizes the spaces to place new pieces.