Jim K wrote:

my point is that if the OP is encouraged to run "24/7" with a *bigger*
stove than your old one, he will have to consider the supply and
disposal of fuel and waste/ashes

So what? He will need to consider those things no matter how big or
small a stove he uses. The dodgy practice I described, of letting the
ash pan cool to room temperature for a short while before tipping it
into a plastic bin was not a recommendation (you should always use a
metal bin), it was merely illustrative to amplify the point that it is
important that one's riddling routine should be such as to avoid the
ash pan being full of red hot stuff while it is taken out of the stove.

Even when one tips it into a metal bin, it's better that the ashes
should be at 200 than at 600 degrees C. The hotter the ash, the more
volatile it is, so it will generate more dust whilst in transit to the
bucket. Also, the hotter it is, and the more you tip into the metal
bucket (especially when it is empty), the bucket itself can get hot
enough to make melt/burn marks on the floor.

and associated crap and filth - *more
so* with coal based solid fuels than wood IME.

Agreed, the risk of finding incompletely burnt (and still glowing) bits
sitting in the ash is lower with wood (provided the stove has not been
recently riddled!). At least this doesn't matter much when using a
metal ash bin.

But using wood for a 24/7 stove will produce a greater volume of ash per
day, the stove will tend to need more than one emptying per day, there is
a greater risk of the stove going out overnight, and it needs feeding more
frequently than if you use manufactured smokeless fuel. You need also to
consider the price of fuel, and to provide suitable on-site storage for it,
and for the same amount of energy you produce per day, you need either more
room or more frequent deliveries when your fuel of choice is wood.

The advantage of a multifuel stove is that you can mix and compromise. You
can burn wood while you're spending time in the room, and then top up with
black stuff for overnight.