I also have a 432.
I originally bought their BattleTech Hex cut-out trays. I suggest you stay away from those. The feet and arms sometimes go over the hex base, making it difficult to insert them.
I ended up buying the "(Gen) 36 Large Model Foam Tray (BFM)" SKU: BF-BFM-36LM - UPC: 21021964910922
They only come in 1" or 1.5". I emailed them to see if they could make that exact pattern, but 2" thick, and they agreed, no extra charge. Essentially, in the special request/instructions of the order, note that you want them cut in 2", and for safe measure, email the rep you talk to telling him the order number, so that they can relay the message. You could see if they will do 2.5", I never asked them.
Why am I recommending these to you? Density. It has 36 slots per tray. You should be able to fit at-least 4 of these trays with 1 topper for each tray. That's more than an
Invader-class JumpShip carrying 3
overlord dropships. Also, 2" thickness will accommodate the majority of 'Mechs. 1 of 10 'Mechs with a size issue is not a problem IMO, it is easy to just cut one foam tray for extra room. Dedicate 1 tray to large units, or however you like to organize your army. Or simply get another tray.
I have run into 'Mechs that are taller than 2", but are sturdy, and I have simply put a topper over them to prevent chipping, and I have not had any issues.
I have also run into 'Mechs which are taller than 2" which I do not want to risk damaging (example: I added antennas). My easy solution, is simply to cut-out some of the foam walls between two slots, and lay it flat instead of upward. You loose some slots, but it works.
I would also look into the "Stacker" boxes they have, to store any additional foam/'mechs you do not plan to take with you.
Here is a pic of the AGoAC 'Mechs, in one of these trays, for reference. The BattleMaster is the tallest of the bunch, and you can see it popping out. The picture is a bit at an angle, if you look at it dead-on, it sticks out maybe 1/4 of an inch. The RA weapon also makes it sit goofy in the slot. This is one, I would possibly remove a wall between slots, to lay it flat. Having said that, I do not have concerns with simply putting a topper over it for this specific mini.