Yup. Both the BoXer and SiamesePCI/InsideOut card were based on the AA+ chip set designed by Mick Tinker. I'm not certain, but the AA+ may have died along with the BoXer and Anti-Gravity...
Anybody know fo sure???
Anyway, it would be the ideal solution. IIRC, it's conceivable it could have provided 100% compatibility for the OCS, ECS, and AGA/AA chip sets... Not to mention it's own additions, plus fact it could/would have been software upgradeable too.