For TC's of that vintage I have had much better results using HP's, TECO's and in particular IGEL hardware to run OS/2 derivatives on.
Could you specify what models you succeeded with installation ?
I own HP T620 (
https://www.parkytowers.me.uk/thin/hp/t620/) and run Windows XP on it for post 2000’s games.
Recently I bought for cheap HP T5720 (
https://www.parkytowers.me.uk/thin/hp/t5720/) but without RAM and HDD so it need my attention.
Also I own Fujitsu Futro S400 (
https://www.parkytowers.me.uk/thin/Futro/s400/). It have the same specs as T5720. I successfully run Windows 98SE on it. Quake 3 on high details plays nice.
Also I have Wyse V30LE and V90L (
https://www.parkytowers.me.uk/thin/wyse/vx0/WyseV90.shtml). They differ only on CPU clock. Both are VIA Eden C7, V30LE has 1,2GHz and V90L 800MHz.
On V30LE I run without any problems Windows Me and 2000. Just swap RAM for those two. For Me I use 512MB RAM and for 2000 swap it with 1GB. HDD is IDE to SD adapter with 32GB card. Like with RAM I just swap them for Me or 2000.
V90L is sitting on a shelf right now. Some plans for it but for now no time to do it.
I also try install ECS 2.1 on both those Wyse via Samsung usb cd/dvd-rom. Unfortunately every time I try to select boot “default values” or “own values” it stops with this error:
CD-ROM sector read error (drive=9F, sector=16, Code=01).
Drive is not faulty because I use it to all the time on those thin clients and my other devices. Also was able to boot ECS 2.1 form it on different computer. No luck with installation but it proves that ECS 2.1 can boot from this Samsung drive.