Because the crosswind air barrier is stand-alone and very effective at removing infectious aerosols, it would be the most beneficial to a building without forced-air circulation. In fact, it would be far more effective against airborne infection than the expense and waiting time needed convert your present system to HVAC with HEPA filtering. Even if you have the crosswind units preinstalled in a distributed configuration then later converting to forced-air heating and air-conditioning, adding those to your existing crosswind solution would only provide a marginal improvement against airborne infection, not justifying the time and expense. If you do convert, you should keep this solution installed as-is. An installation of distributed crosswind units would have almost surely prevented this large outbreak that resulted in one death in a residence:
https://ici.radio-canada.ca/nouvelle/1746866/cas-covid-19-matane-residence-batisseurs-eclosion-foyer