I'll preface this by saying that while I understand that, at least in the game's current state, resources are mostly infinite, BUT their generation rates are not and that's where this issue actually becomes an issue.
Reinforced Iron Plates are extremely resource and labor intensive for their tech level and this becomes glaringly apparent when you're building conveyor belts and realize it's far cheaper and easier to build Mk. 3 belts than Mk. 2. because it's actually harder to produce the plates needed for Mk. 2 belts than it is for the Mk. 3 belts, which I find to be pretty silly. It takes a total of 12 iron ingots to make a single reinforced iron plate, whereas it takes 3 steel ingots to make a single steel beam.
If you convert that out into purely raw costs, it's 12 iron ore to make a reinforced iron plate (4 plates (8 ore/bars) and 24 screws, (which takes 4 iron rods, which themselves are 4 iron ore/bars)) vs 4.5 iron ore and 4.5 coal to make a single steel beam (3 iron ore and 3 coal makes 2 steel bars. Need 3 steel bars per steel beam). However if you have the alternate steel bar recipe, like I do, you can make a steel beam with 3 coal and 1.5 iron ore (3 iron bars (3 ore) + 6 coal = 6 steel bars).
There is an alternate screw recipe that uses 2 iron bars to make 12 screws, but that still works out to 4 iron ore per 24 screws so it doesn't change the materials needed, just lowers the processing time and power requirement.
On top of being more resource intensive, it's a lot more labor intensive to make the reinforced iron plates. Assuming you have no alternate recipes, you have to convert iron ore to ingots at a rate of 1:1, then in at minimum 2 constructors, convert those ingots into iron plates at a rate of 2:1, 2 ingots per plate, and also iron rods at a rate of 1:1 THEN you have to convert the rods into screws in yet another constructor at a rate of 1:6, 1 rod per 6 screws, and then finally feed all your plates and screws into an assembler to make the reinforced iron plates. Steel beams on the other hand are simply run the ore and coal through a smelter to make steel, feed it directly into a constructor to make steel beams, done. You can cut out the middle constructor on the screw line if you have the alternate screw recipe, feeding iron ingots directly into the constructor to make the screws at a rate of 2 ingots per 12 screws (same resource cost as normal), but it still ends up taking a lot more resources, power, and a lot more time than making the steel beams.
I know there's also alternate reinforced iron plate recipes but looking at them, they still take a lot more time and resources to make than the steel beams.
Maybe something like 6 iron ingots to make a reinforced iron plate in a constructor rather than an assembler. It's less resources than what they currently need with far fewer machines and less time needed to produce them. Production time should be on par with steel beams, but fewer, simpler resources, which is more appropriate to the tech level. It would also make it a lot easier to create items that need the reinforced plates, like the modular frames.