fascinated by that, Tattie, but as I said earlier, the Irish BC PAOLO players have always managed with with either no chords at all , or a quick rattle at unrelated chords which amounts to percussion.

Mention of sheet music maybe illustrates one reason for the question at the root of this discussion.
I know there are informal sessions in Scotland where the 'dots' are a rarity, but the standard big box, button or piano has maybe set a subconscious pattern where 7ths, diminisheds & suchlike are important, you'll know that ceilidh dance bands & strathspey & reel society musicians invariably play from music.

So has the value placed on playing the 'right' chord filtered down to smaller semitone/melodeon players & the interest in the bass side apparent here? Setting up music stands to ensure 'correct' chords inevitably detracts from the spontaneity which makes for a good session- and less attractive &to the casual 'joiner-in.

After all, when did you last see an Irish musician or ceili band playing from music? Either approach is valid of course & they are two separate traditions but I've always kept things simple & will continue to do that, having hardly ever found the dots any use at all.
And I've stayed at yours, non-Charlie, so be sure theres's always a welcome here in the Machars, even for a BC player....