There are a number of low cost options for dealing with this:
First thing is to cover the big magnifying glass up front from the outside with a light colored sunshade.
Change or Clean the AC filter WEEKLY and be sure to clean the coils at least annually. The previous owners did not keep the coils clean on mine so it took a number of cleanings before I got them fully clean and free flowing. I would have needed to remove the unit and disassemble it to get it done in one session.
Keep the roof clean and white so it does not become heat soaked and resist the temptation to paint it a color. In sunny hot locations "White is Right" as far as roofs are concerned.
If you do not already have them, install roof vent covers to keep direct sun from beating directly on the vent lids. The lids will last longer too. Also be sure to insert an insulating vent cushion from the inside to make up for the insulation removed when they cut the hole for the vent in the roof.
Deploy your main awning and keep it pitched as close to the ground as practical without turning it into a head banger to keep the sun from beating on the side of your Motor Home with the entry door.
Avoid cooking meals inside that take a long time to cook or involve boiling pots. There are three burners on your stove (1 @ 9,000 BTU and 2 @ 6,500 BTU) which combined put out 22,000 BTU's of heat plus an oven so using them especially for long periods of time can easily overwhelm a 15,000 BTU Air Conditioner when its over 100 degrees out. I use a 2 burner electric buffet range or a portable gas grill outside when its hot and humid here in Florida. Think 100 degrees real and 120 or more effective due to humidity so high your clothes can take hours to dry out on a clothes line. Walmart has a basic 2 burner electric model for around $23. https://www.walmart.com/ip/Mainstays...rner/273668612
Avoid Long Hot Showers meaning showers longer than 2 to 5 minutes using more than tepid water and be sure to turn off the water when not wetting or rinsing off.
Use external sun screens or awnings on the side windows and if window awnings are used keep them pitched down to prevent the sun from shining directly on the windows.
If boon docking and running the generator consider using a fan to blow the heat from the generator out from under the coach. Even after the generator has turned off it can take hours for the heat to dissipate after its been turned off.
Have reasonable expectations. Too many from the North come down to Florida and expect to literally cool their motor homes to temperatures in the 70 degree range or lower while the accepted norm for the locals here is a chilly 80 to 82 degrees so that they will be better acclimated to deal with the temperatures when they step outside. You really won't have much Fun in the Sun when your body is acclimated to temperatures much below 80 and the effective temperatures outside are between 110 and 130.
If you have the PowerLine Management System in your coach it may already be set up to support a second AC unit on a 30 amp service. You do however need to be careful not to use high draw electrical items for extended times during the hottest parts of the day since PowerLine will turn off the second AC when other electrical loads outside of its control are turned on.
I live in Florida and camp in sunny locations during the Dog Days of summer with my 30 amp 2001 Adventurer 35U. Yes it has a more residential system with two sets of condensers and two compressors however even on a 20 amp service running only 1 compressor using the methods listed above it is able to keep up plus its 4 feet longer and has more roof vents and windows than the Intent 31P.