I've used 4nec2 to analyze over 800 different Antenna Designs.....and have looked at a LOT of Antenna Builds....so I can help you chose an appropriate DIY Antenna....but I'm NOT in the Antenna Construction/Installation business....
I've looked at a LOT of user installation reports, but I do NOT recall ANYONE using Angle Extrusion rather than Circular Rods. Obviously, Angle Extrusions would have a MUCH higher wind resistance....and may or may NOT break sooner than Rods....it would depend a LOT on the inherent strength of the chosen metal formula....I would ALSO be worried about how it holds up to wind induced vibration.
Since an outdoor antenna needs to survive high winds [esp. in your location], I would highly recommend that you stick with what we know WORKS...namely 3/8-in Aluminum Rods.
Although very useful, TVFool isn't always being updated with latest changes....your area (Phase 2) finished the "Channel Repack" on 21Apr2019, and I'm pleased to see that TVFool shows the new Channels for WFSG (Ch28) and WBIF (Ch26)...but does NOT even show WJHG (Ch16). Hence, we also want to look at your www.rabbitears.info
"TV STUDY" Report [post Repack at 30-ft height]:
[This is for the zipcode location (Post Office???) more than 5-mi from TVFool location....you can enter your address for a more accurate report]
First of all, FORGITABOUT receiving WDIQ (PBS) on weak Ch10....it's on Second Harmonic of Extremely Strong [-7.6 dBm] FM Station on 96.9 MHz....which would likely explain why it is NOT included in RabbitEars list.
Note that RabbitEars Report adds WFRW (IND) on strong Ch14 [NM=62.9 dB per R-E] and WJHG (NBC/CW) on strong Ch16 [NM=31.2 dB per R-E]....and for some reason I/we do not YET understand, calculates MUCH higher signal strength for WDHN (ABC) on Ch21 (NM=34.8 dB vs 18.3 dB per TVFool) and WDVX (FOX) on Ch33 (NM=17.1 dB vs 2.1 dB per TVFool)...and significantly LOWER signal strength for WFSG (PBS) on Ch28 (NM=5.6 dB vs 13.3 dB per TVFool).
You "should" receive (i.e. NM>10 dB) fol. NETWORKS: CBS on KTVY (Ch36), NBC/CW on WJHG (Ch16) ABC on WDHN (Ch21) [as well as WMBB (Ch13, Hi-VHF Band)] and FOX on WPGX (Ch9) [and MAYBE also WDVX (FOX) on Ch33]. So it is UNCLEAR whether you NEED a Hi-VHF Band Antenna [to receive FOX on Ch9 instead of Ch33], in addition to a UHF Band Antenna.
IF UHF-Only, a simple SBGH with 4 or 6 Pairs of Reflector Rods "should be adequate". You've probably seen Autofils's SBGH on-line drawings with 7.08-in=180-mm Zig-Zags at 45-deg Angles and 5.0-in=127-mm Horizontal "Spurs", which you will find for both with and w/o 6-Pairs of Reflectors in my fol. Analysis for the No Reflector Version:
[Autofils's SBGH w/o Reflectors Analyzed]
OR nikiml's GH4 (4-Pairs of Equal Length Reflector Rods) with Optimized Dimensions for slightly improved performance:
nikiml's Antenna pages - GH4 UHF antenna
[nikiml's Optimized GH4, Dimensions in figure]
OR nikiml's GH6 (6-Pair of Un-Equal Length Reflector Rods in a more complicated Array):
nikiml's Antenna pages - GH6 UHF antenna
[dimensions in on-line Figure]
IF you want BOTH UHF+Hi-VHF, a G-H type Antenna COULD get more complicated, adding a Hi-VHF "Top Hat" (shown in Black) and possible a SECOND set of Longer Reflector Rods (shown in Blue color), such as Autofils version cited above....and (similar?) jed versions reported here:
nikiml's Antenna pages - GH*n3 jed mods
[jed's GH4n3 WITH Hi-VHF mod]
OR even better, nikiml's GH4n, which "should be adequate" and is a bit simpler than the higher Hi-VHF Gain variations:
[In figures, select GH4n version]