Have the glides upgraded to 100 lb capacity (heavy duty).

Several years ago in my garage I made a bunch of cabinets to store tools in, drawers were made out of 1/2" plywood (sides, front, back and bottoms) I used left over blum undermount slides that were rated for 75LBS

One cabinet was 36" wide, top drawer 6" high....I have that top drawer loaded with every ratchet and socket I own, and if I were to guess there is at least 200lbs of weight in it....just opened it this morning and still works good as new, soft close worked perfectly also

I think you will be fine if you are a few pounds over in your drawer, nothing to worry about

My cabinetmaker put glides rated for 250 lbs. on some things. These don't have soft closers, but I don't care, and it made him feel better. :) These are my cutting boards pullout (which didn't need it but I mentioned maybe putting a marble pastry board there), my six foot tall pullout spice rack, mostly for the weight of the rack, and my 48" wide pot drawers full of Le Creuset. They also have heavy bottoms.

All of the rest of my glides are rated for 100 lbs., including the rollout tray shelves in the pantry, and I don't worry about what I put on them, including heavy grains and liquids. I have the crockpot, waffle maker and a number of other small appliances in one drawer, and the toaster oven, juicer, cuisinart, some kind of electric sandwich grill my mother gave me and the vacuum sealer in another.

If the drawers aren't going to suit your needs and can't be upgraded, perhaps it really is time to shop anew.

Thanks sjhockeyfan, athomesewing, ajc71 and pllog. We are meeting with the KD later today-I will check if we can upgrade the glides to 100lbs. I am not sure if we can change the thickness of the bottom in this line. I will check if the upgrade to metal drawers will make it any better.
ajc71, it is good to hear that 1/2" plywood can take that much weight. I will see if the GC or DH can retrofit the few drawer boxes that need to be upgraded from 1/4" to 1/2".
So many things to consider..it is just mind boggling! I can't imagine how people just go into the store and say I will take that kitchen!

Blum has new full extension/ soft close drawer hardware.
Old Runners:
Blum 562 series - 75 lbs dynamic/100 lbs static
Blum 568 H series - 110lb dynamic/125 lbs static - heavy duty
New Runners:
Blum 563 series - 90 lbs dynamic/100 lbs static
Blum 569 H series - 135 lbs dynamic/150!lbs static
My cabinet manufacturer was still carrying the old runners when my cabinets were ordered, Feb., 2013. I had the hardware for four 36" drawers switched to the heavy duty 568H series in March, 2014. The soft close on my dish drawer stopped working & through GW I figured out it was a weight issue. With the 568H runners installed, my drawers feel stable & the soft close works, although I do wish I had upgraded to the even heavier 569H series.
My experience with my KD was overall very good but the company she works for didn't know Blum heavy duty drawer runners even existed. She contacted her rep at Woodmode/Brookhaven, who was also clueless. I had to provide them with part numbers. It seems to me that if you are going to sell 36" or wider drawers, you should advise your customer to purchase heavy duty hardware.
I've attached a link with all the Blum info about part numbers, weight limits, etc.

Here is a link that might be useful: New Blum Tandem Plus Blumotion Drawer Runners

Wow! thanks Romy718. That is super helpful to know. I will pass it along to the KD. I am not sure Ultracraft uses Blum hardware. I think they do. Maybe he can get the new ones for us. But, I will still have the issue of 1/4" plywood bottom. Don't know what the appropriate solution for that is.

vinudev_liny, Did you meet with your KD? Did they have any solutions for you? I am meeting with a KD who carries ultracraft later this week and these same issues would be a deal breaker for me!
Thanks!

Thank you Romy718! I just printed this post for my kitchen files and I will save it also.