Some time ago we contacted SolusVM to discuss the issue. We received information that API command to automatically resize server, will be available in the next release. Once the API will be ready, we will immediatelly add it to the module. There is no workaround possible for now.
Functionality works but it's not automated yet. It sends an email for SolusVM server owner with all the update details and updates all the resouces in the module. It also updates the resources billing connected with Advanced Billing For WHMCS.
Hopefully, improved API will be ready soon. We are waiting for it.
We didn't forget about the promo, therefore we prepared special packages allowing you to purchase more modules and pay less. It will be cheaper to buy VPS + Cloud + Reseller in one package than all the modules separately or just VPS only. It will be even more cheaper if you decide to purchase DNS Manager For WHMCS and/or Advanced Billing For WHMCS. Information about promo packs is listed on our website: http://www.modulesgarden.com/products/whmcs/solusvm_extended_modules/pricing