Should I abandon my 80m loaded coil antenna project?

I have been trying to get my homebrew 80/20m loaded coil dipole antenna for restricted spaces resonate on 80m for quite some time. Little bit of collateral successes has been there in between. I have been able to get spotted on 30m with this antenna at VU2PTT on Reverse Beacon Network at 171 miles with up to 20 dB signal to noise ratio. I have been able to have SSB and CW QSOs on 20m to Indonesia and SSB QSO to Thailand, with this antenna, in the process of tuning 20m segment. VU2XPZ was able to copy my CW signals on 30m at a distance of 79.3 miles. He opined that this antenna is working on 30m as the third harmonic of 80m, that is 3.5 MHz band antenna working on 10 MHz. When I calculated the one third of the resonant frequency, the resonance on 80m band would be at 3.37 MHz, which is below the amateur band which I can test. That would be the reason for HI SWR on 80m amateur radio band.

With that information, I started folding back the ends of antenna by six inches each time. After the fourth six inch, further folding needed trimming as well as the folded ends reached the loading coils. Hence in the last attempt I trimmed off 12 inches and folded 12 inches. With this, the resonance point on the 30m band shifted upwards, as expected and the 30m band showed SWR 2 instead of the previous 1.1. 20m band continued to have SWR above 5 and 80m still having HI SWR. It seems I have reached a roadblock in this antenna project. Looks like I will not be able to proceed further without having an antenna analyzer like nanoVNA or RigExpert! Still I am happy that it was a great learning experience and learned the new point of 30m operation with 80m antenna as third harmonic. Though I have operated on many odd harmonics earlier, even for satellite contacts, somehow the fact that 30m band is the third harmonic of 80m did not strike my mind till VU2XPZ told me yesterday.