Reading your first post again Jimmy, may I add a word of caution about your expectations if you go down the route of bespoke waterslide decals. You made a mention of a "blunt" edge with your own made decals with proprietary inkjet printer decal paper when you cut them out from the carrier sheet after applying a sealing coat.
In most made to order "one off" designs it is most likely that the absorbent paper backing sheet will have a full
all over coating of adhesive/carrier film, then the actual design that is printed only as it appears and finally an
all over sealing coat covering the whole sheet. That's the problem with most bespoke work - As a result of this process individual items must be cut from the sheet, potentially leaving a prominent, blunt, edge on the decal.
With volume produced decals, that you may be comparing the bespoke type to, they differ in one significant way from most made to order "one off" designs - The adhesive layer, carrier film, printed design and sealing coat are
all probably printed serialy on to the absorbent paper backing sheet by an offset process. This allows a close match of each layer applied to be planned to match that of the printed design alone, also allowing for voids to be made within a design's area too. I.E. You have a lot of individual items that do not need to be cut out and appear to have "feathered" edges giving the impression of a near printed on livery when applied.
The "blunt edge" effect can be masked/minimised in part by 1) Cut out decals from a sheet using a fresh sharp scalpel blade. 2) Make sure you have a good smooth gloss coated surface to apply them on. 3) Using a product like Microscale Micro Set, that will help remove air bubbles from forming behind and from the edges of the decal as it drys. 4) A decal solvent, say like Solvaset, that will help stop any further curl in the decals' edges so it snuggles down well to a given surface and any imperfections or texture 5) Apply an overall self leveling lacquer coat to provide a suitable finish and protection. Be careful that the decals supplied to you do not react adversely to any of the products used in steps 2/3/4/5.
Ask a potential supplier if they have a lower cost "stock" design they could supply for you to have a go with and see if they have any limitations, in your eyes. A specialist supplier may well be using a finer grade of prepared decal paper than you have available to you and a sealing coat that is again thinner in application, resulting in a more satisfactory final result. Sorry if I am teaching my grandmother to suck eggs here, it's not the intention

Max