European trade market means more taxes collected which means more money available for forces.
That is why the
max tax rate is
already a factor in the
algorithm for calculating the size of the
"Royal Expeditionary Force".
(And
max tax rate - by the requests for tax increase / donations - is mostly influenced by the
amount of goods you trade - but also other factors, like
King attitude.)
A
huge standing army needs
a lot of upkeep, so "one time payments" causing an increase of the REF
wouldn't be very immersive.
(Also no Nation in the World
would simply waste money to buy troops if there is
no reason to do so - which there isn't
as long as the colonies don't mobilize.)
By the way:
The
WTP tax rate and
REF algorithms are
extended and improved versions of the custom algorithms originally developed in
TAC (by a complete team of modders).
There has been
a lot of design thinking been put in there by people that
really understand the game logic and how
non-linear algorithms may be balanced.
it should change the way we trade and decide how we move forward with the colonies.
That is
exactly the intention of the algorithm already, so I
don't really understand the problem.
(And yes
it already "reflects" trading effects, just maybe not as direct as you may want it to - but that is for good reason.)
-------
The chain of effects is (very very simplified) like this:
(But again, there are
many other factors other than
trade / taxes, that also increase
REF.)
1) More Trade
2) More Tax Requests / More Donation Requests
3) Max Tax Increases / Worsening the King's Attitude
4) Larger REF (in both cases eventually)
So if you
trade a lot, you will
eventually increase the REF one way or another.
But
you can also balance it a bit by keeping your army low and behaving nicely to the King.
You are just
not directly punished for trade - because considering
game design it would be
complete non-sense to
(directly) punish successful gameplay.
The algorithm instead
works on a level of "diplomatic" relations how you
interact with your King. (Which is both
immersive and
logic for gameplay.)
So the
player still has a choice to
drive up REF or not by the reactions in the diplomacy dialogues or how he e.g. drives up Rebel Attitude or mobilizes or ...
In your solution he
simply wouldn't have that choice anymore because a
good and successful gameplay would be punished ...
-------
The
REF algorithm developed in
TAC (and improved in
RaR / WTP) covers
lots of different aspects.
(Max tax rate is just one of them but there are many other factors also considered, e.g. Rebel Percent, Military, ...)
Most important however is simplified the
"threat of Declaration of Indedendence".
(Because why should the King otherwise waste money if the colonies behave perfectly nice.)
---------
Do you really feel that the REF is too small?
Actually most players complain that it is too big.
If yes, see below.
It is most likely due to your settings.
---------
... but I think 50% of all taxes collected ...
Please let us
stop discussing about
messing with an algorithm
as complex as the "REF-algorithm".
It is
not a linear algorithm with
simple "+" calculation but
a non-linear algorithm with lots of
variables being weighted.
I am really not in the mood to
waste time re-inventing or re-balancing algorihms that have been working perfectly fine for almost 15 years.
It is really proven in use and considers basically everythig that is in any way relevant for the relation between King and Colonies.
Also
directly punishing good and successful gameplay is really
bad game design.
(It is both counter intuitive and also not fun, nor is it immersive or logic.)
And again, why should the
King increase his army as long as the
colonies behave nicely?
(Would a King really consider
trade and tax income a
hostile action that needs to be worried and feared?)
----------
Sorry but this discussion is really a bit pointless.
(Which is most likely the reason nobody had answered so far.)
There has never been an issue with the REF algorithm, so why mess with it ? 
Does it need to be changed
just because players don't understand how it works?
That may be a
reason to explain, but
not to change ...
And actually it has been
explained like 10 times already in the last 15 years.
And do we really want to
punish successful gameplay?
Increasing REF endlessly just because the player sells goods ...
Or having the King
react more hostile by additionally increasing the REF for
accepted tax increases ?
In reality just the contrary would happen if a colony nicely accepts taxes and relations are beneficial.
-----------
If you feel the REF is too small, simply play higher Handicaps.
(Or simply change the balancing factors in "GlobalDefinesAlt.xml")
Also if you play on larger Maps, the starting REF will also be bigger.
(It already considers the fact that the Player will get e.g. more Gold from Goodies.)
But we will definitely not mess with the algorithm itself as you suggested.
(It would completely break all reasonable gameplay balancing of the mod.)
