Another druid trick I found. You can cast Speak with Animals then switch that spell out with another prepared spell and keep the effect on yourself. So Speak with Animals only costs a first level spell slot. It doesn't use up a prepared spell slot too.
IMHO it's a pity they did not stick with "Druids will not wear armour and shields made of metal" as per the PH page 65
To be fair this was always a weird flavor rule rather than a hard mechanical limit. The rule says "you will not" rather than "you cannot" and offers no explanation as to what will happen if you actually try it unlike older editions. It is more like a legacy rule than something that matters a lot as far as game balance goes.
It also doesn't make too much sense in modern lore. Clerics can channel the life or nature domains just fine in metal armor and they're drawing from basically the same source if they worship a nature god. Wizards don't suffer casting penalties in heavy armor so long as they have the proficiency. And I can't imagine a dwarf druid who grew up underground around metalworkers would consider worked metal to be more unnatural than treated wood or cured animal hide.
Being from 1st Ed AD&D, I'm used to the druid being restricted to "natural" armor. Now, you could argue that worked metal is natural, but not in the eyes of the druid circles. In regards to dwarf druids, these were extremely rare (see Pikel Bouldershoulder in The Cleric Quintet) Not unheard of, but extremely rare, and they tended to adopt the druid way of life as opposed to incorporate their own society's preferences. The original druids also didn't worship gods. The believed in the raw power or nature and in the balance of life an death as opposed to such power coming from a particular god. Most gods will lean toward, Order, Chaos, Good or Evil. Druids believed themselves to be the fulcrums of such ideals, maintaining the balance between all such forces.
Metal wasn't so much unnatural as it was too processed for their use. Through the use of metallurgy, ores are combined, heating and bound into new compounds, then heated again, pounded and shaped into what is required. The druids believed in minimal processing, hence why leather, hides and wood were used.
Weapons were more symbolic than anything. Daggers could be used, but they were usually made out of bone and the like. Sickles and scimitars represented the crescent moon, and as such were allowed to be used. Even then, most ceremonial sickles were made from silver or electrum, metals of the sun and moon in balance.
1st ed druid society was VERY strict. It was difficult to enter into the druid circles, and once there, you had to abide by their laws and society. This was offset by the ability to cast powerful spells of nature and, of course the ability to wild shape. So I believe they definitely should return back to druids only being able to wear non-metal armor, if nothing else, for balance, but also to keep the feel for druid alive. This is just my opinion, however.