In production, only 1 Canada Tax Regime set up at Country Level years ago. A new enhancement reques

In production, only 1 Canada Tax Regime set up at Country
Level years ago.  A new enhancement
request come in, and need to have Quebec tax rate ( GST + QST) separated and
calculated the tax amount .  From  DOC 1063491.1 & 577996.1, it seems  need  2
Tax Regimes at province level, and check ‘Allow Cross Regime Compounding’, and the compounding
Precedence on the GST regime should be lower than the precedence on the PST
regime.  However, the existing tax regime
is setup in Country level and does not allow to update Cross Regime
Compounding. 

Is
there a way to keep ONE Canada Regime at country level and still do compounding