Is this yellowing normal? Probably because of LST?

the reason for older leaves yellowing and dying off is a low amount of nitrogen that's available in the plant.. nitrogen is a mobile nutrient, so the plant can pull it from areas where it's less needed (old growth) to areas where it's more needed (new growth.. nitrogen is important for the growth of the plant).. In general it's nothing to worry about, but i would up the amount of N in your fertilizer a little bit to avoid this spreading much further. happy growing :)

High there! Nothing alarming, if its only low leafs. The plant search to move mobile element to new leafs, trying to reach much light. Monitor this.

Привет, друг! 👋 Желтение, отмирание и отпадение самых первых листьев растения - естественно! Нет причин переживать! Это естественный процесс в растении, тем более, учитывая его возраст! 👌 Всё хорошо, всё в норме! 👌 Удачи, братан! ✊😇