Compiled from Wikipedia’s format list, Microsoft Store capability text, and wps.com’s file-opener page (Kingsoft cites dozens of formats, including a “47 formats” claim on the opener feature page).
Writer / text
wps, wpt, doc, dot, docx, dotx, docm, dotm, rtf, txt, xml, htm, html, mht, mhtml. Store listings also mention e-books mobi, epub in some SKUs.
Spreadsheet
et, ett, ets, xls, xlsx, xlt, xltx, csv, xlsm, xltm, xlsb, plus DBF/DIF and various data-source types in Store copy (odc, udl, dsn, iqy, dqy, mdb, accdb).
Presentation
ppt, pot, pps, dps, dpt, pptx, potx, ppsx, pptm, potm, ppsm (Wikipedia also lists dpss).
PDF and images
pdf for read/annotate/convert. Image round-trips for insertion; Photo module for crop/annotate. PDF toolkit is where Pro gates appear.
Google files
Marketing claims Google Docs/Sheets/Slides compatibility. In practice: download as DOCX/XLSX/PPTX from Drive, then open in WPS. Native .gdoc shortcuts are not Word files.
Do not let WPS own every extension
Being able to open a type is not the same as wanting it as the default handler. Fix associations.
What to send other humans
DOCX, XLSX, PPTX, PDF. Not WPS/ET/DPS unless they also run WPS. Not Pages. Not a Google “.gdoc” shortcut file. If they are on Word 2010, avoid the newest 365-only features in the file you send.
What to archive
PDF/A if you have a specialist need; ordinary PDF plus DOCX source is what most people mean by archive. Keep the source. A PDF of a scan of a printout is a dead end.
CSV is not a sheet
CSV has no types, no formulas, no sheets. It is a dump. Import with UTF-8. Export with UTF-8. Document the delimiter. Excel in some locales still opens UTF-8 CSV as garbage until you use the import wizard — warn the recipient.
Opener marketing: Kingsoft cites dozens of types including 47 on the file-opener page. Being able to open is not the same as round-trip fidelity. Test.
Macro formats
DOCM/XLSM/PPTM can contain macros. WPS may open the file and ignore or partially run macros depending on SKU and a VBA add-on. Treat unknown macro files as hostile. Convert to DOCX/XLSX if you only need the content and you trust the content.
.doc binary
Still everywhere in government inboxes. WPS opens many of them. Save out as DOCX unless the recipient’s system is stuck in 2003. Round-trip once. Complex field codes may flatten.