Access to a laser cutter! Cool! Weight is relative. I'm familiar with the Line Audio mics from folks here at TS using them but have not used or handled them myself. I do recall another discussion where they were deemed too heavy for the rig being discussed (I think Voltronic posting about his modular thin carbon-fiber tubing 'T' stand designed for miniature DPA omnis), but that doesn't mean they are any heavier than other mics of similar size. I'd think several identical laser-cut 1/8" ply parts (luan door skin material?) laminated together would do the trick without sagging or failure. Once you get familiar with how much adjustabilty you really need and converge preference you might move to something like audBall's setup.. or go with something off-the self and modular like the smallrig.com stuff kindms and rocksuitcase are using which look well built and not over-priced - but you will still need to figure out what you want to get the right bits to assemble. I see some stuff on that site I might pickup for my own rig.
I really like audBall's setup pictured at the above link. It's clean, not visually intrusive, and adaptable with modular-width arrangement tailored to fit the situation rather than having unused bar extending out beyond the mics. It does appear its fine-grained width-adjustability is somewhat constrained by the length of individual segments. But I imagine a few shorties in the mix along with some longer ones might help with that. My take on it is that something like that setup would be an excellent option once you determine a few typical spacings that you end up using most commonly. For determining what those spacings might be you might want something easily and infinitely adjustable that is inexpensive to mess around with - a DIY laser-cut slotted bar made out of ply could serve that temporary role.
Something you might consider is shock mounting the bar itself where it attaches to the articulating arm, with the mics rigidly mounted to the bar, rather than individual suspending each mic on the bar. Advantages are a cleaner, more compact and streamlined arrangement aloft, providing less visual occlusion and less windage; easier setup with a more tightly constrained relationship between the two mics (or more); less stuff up there that might get knocked askew; and the potential for improved isolation by way of the increased suspended mass and its higher at-rest inertia. Disadvantage is needing to determine the appropriate suspension spring rate for the combined weight of bar, mounts and mics (stiffer elastics in the Rycote duo Lyre or whatever) and how it connects to the bar. See again the photo of audBall's arrangement above. If you didn't know it was there you might not even notice the Rycote Lyre suspending the bar at first glance. Really nice job on that setup Horus! Like he mentions, getting to a really optimized arrangement like that is a journey.
I use telescopic TV "rabbit ear" antennas and some custom made attachment parts in my DIY setup. I really like the antennas as they provide an extremely wide-range of easy and rapid adjustment, and fold/telescope down compactly, but they are somewhat delicate and are really only able to support light-weight miniature mics such as your AT 853s or the miniature DPAs I use. The central hub supporting them and the cabling has a mounting stud that can be attached to a tall stand, low foot, extension bar, clamp or whatever depending on the situation. I don't currently use shock mounts with it, but plan to add a single complaint "floater" suspending the entire array as discussed above, connected to a ball-mount - and I see one that might work at smallrig.com, thanks kindms. It's certainly been a journey.
Edit- I see voltronic just posted prior to this post. Correct me if I misspoke about the relative heft of the Line Audio mics above.